{
    "title": "Mn-inlaid antiphase boundaries in perovskite structure",
    "pre_title": "Mn-inlaid antiphase boundaries in perovskite structure",
    "journal": "Nature Communications",
    "published": "07 August 2024",
    "supplementary_0": [
        {
            "label": "Supplementary Information",
            "link": "https://static-content.springer.com/esm/art%3A10.1038%2Fs41467-024-51024-2/MediaObjects/41467_2024_51024_MOESM1_ESM.pdf"
        },
        {
            "label": "Peer Review File",
            "link": "https://static-content.springer.com/esm/art%3A10.1038%2Fs41467-024-51024-2/MediaObjects/41467_2024_51024_MOESM2_ESM.pdf"
        }
    ],
    "supplementary_1": [
        {
            "label": "Source data",
            "link": "https://static-content.springer.com/esm/art%3A10.1038%2Fs41467-024-51024-2/MediaObjects/41467_2024_51024_MOESM3_ESM.xlsx"
        }
    ],
    "supplementary_2": NaN,
    "source_data": [
        "/articles/s41467-024-51024-2#Sec15"
    ],
    "code": [],
    "subject": [
        "Ferroelectrics and multiferroics",
        "Transmission electron microscopy"
    ],
    "license": "http://creativecommons.org/licenses/by-nc-nd/4.0/",
    "preprint_pdf": "https://www.researchsquare.com/article/rs-3884985/v1.pdf?c=1723115294000",
    "research_square_link": "https://www.researchsquare.com//article/rs-3884985/v1",
    "nature_pdf": "https://www.nature.com/articles/s41467-024-51024-2.pdf",
    "preprint_posted": "04 Feb, 2024",
    "research_square_content": [
        {
            "section_name": "Abstract",
            "section_text": "Improvements in the polarization of environmentally-friendly perovskite ferroelectrics have proved to be a challenging task. In contrast to traditional methods by complex chemical composition designs, we successfully formed new Mn-inlaid antiphase boundaries in Mn-doped (K,Na)NbO3 thin films using pulsed laser deposition method. Mono- or bi-atomic layer of Mn has been identified to inlay along the antiphase boundaries to balance the charges originated from the deficiency of alkali ions and to induce out-of-plane tensile strain in the KNN films. Thus, rectangular saturated polarization-electric field hysteresis loops have been achieved, with a significantly improved twice remanent polarization of 114 \u03bcC/cm2, which can be comparable to that of typical PZT thin films. Moreover, the Mn occupation at the A-site of the KNN perovskite structure was directly revealed using atomic-scale microstructure and composition analysis. The Mn-inlaid antiphase boundary can further enrich the understanding of perovskite crystal structure and open up new possibilities for the design and optimization of perovskite materials.Physical sciences/Materials science/Condensed-matter physics/Ferroelectrics and multiferroicsPhysical sciences/Materials science/Techniques and instrumentation/Microscopy/Transmission electron microscopy",
            "section_image": []
        },
        {
            "section_name": "Additional Declarations",
            "section_text": "There is NO Competing Interest.",
            "section_image": []
        },
        {
            "section_name": "Supplementary Files",
            "section_text": "SupplementaryInformation2.pdf",
            "section_image": []
        }
    ],
    "nature_content": [
        {
            "section_name": "Abstract",
            "section_text": "Improvements in the polarization of environmentally-friendly perovskite ferroelectrics have proved to be a challenging task in order to replace the toxic Pb-based counterparts. In contrast to common methods by complex chemical composition designs, we have formed Mn-inlaid antiphase boundaries in Mn-doped (K,Na)NbO3 thin films using pulsed laser deposition method. Here, we observed that mono- or bi-atomic layer of Mn has been identified to inlay along the antiphase boundaries to balance the charges originated from the deficiency of alkali ions and to induce the strain in the KNN films. Thus, rectangular saturated polarization-electric field hysteresis loops have been achieved, with a significantly improved twice remanent polarization of 114\u2009\u03bcC/cm2 with an applied electric field of 606\u2009kV/cm, which can be comparable to that of the typical Pb-based thin films. Moreover, we directly see the Mn occupation at the A-site of KNN perovskite structure using atomic-scale microstructure and composition analysis. The Mn-inlaid antiphase boundary can further enrich the understanding of perovskite crystal structure and give more possibilities for the design and optimization of perovskite materials.",
            "section_image": []
        },
        {
            "section_name": "Introduction",
            "section_text": "High-performance perovskite ferroelectrics are central to various electro-mechanical functional devices1,2. However, the use of toxic Pb-based ferroelectrics in high-end applications is being limited due to environmental concerns and the related legislations3. As an eco-friendly alternative, lead-free perovskite potassium sodium niobate (KxNa1-xNbO3, KNN)-based perovskite ferroelectrics materials have been intensively studied since the discovery of a large piezoelectric coefficient d33 value of 416 pC/N for KNN-based ceramics by Saito et al4,5,6. With advancements in the ferroelectric performances of the KNN-based ceramics and single crystals7,8,9,10, a great deal of efforts have also been made to prepare the KNN-based thin films by various deposition techniques11,12,13,14. However, the volatilization of the alkali ions has been identified as a major issue in obtaining high-quality KNN-based films. The inevitable loss of potassium and sodium elements during the vapor or chemical solution-based depositions changes the stoichiometry, resulting in the formation of undesired alkali-deficient secondary phases and defects. Consequently, the KNN-based films exhibit high electrical conduction and poor ferroelectric response15. Previous strategies focused on chemical composition adjustment to compensate for the elemental volatilization, and construction of morphotropic or polytropic phase boundaries to enhance the dielectric and ferroelectric properties of KNN-based thin films16,17,18,19.\n\nRecently, some other methods, such as interface effects, flexible substrates, and defects engineering have been explored to modulate the lattice strain, displacement polarization and electronic structure11,12,20,21,22,23. All those efforts have led to a gradual improvement in the overall ferroelectric performances, however, which still remain significantly inferior to that of Pb-based films and thereby are far from being suitable for practical applications in micro electro-mechanical devices, ferroelectric field-effect transistors, nonvolatile memories and electro-optic devices, etc1,24,25. Material properties are strongly influenced by the microstructure. In terms of crystal structure, the above-mentioned attempts primarily focused on distorting or tilting the lattice within the basic perovskite framework, which has given rise to limited effects in improving the ferroelectric properties. It has been observed that the physical constraints of the underlying substrate and the large unit cell of oxide perovskite structure can lead to the generation and propagation of out-of-phase boundary defects through the entire thickness of the film, especially with special deposition processes12,26. These charged out-of-phase boundaries, originated from the alkali-deficiency, have been identified and found to play an important role in the piezoelectric performances of the NaNbO3 films12.\n\nIn this work, we also harnessed these inherent characteristics (alkali deficiency and out-of-phase boundaries) to create a nanocolumnar structure and then incorporated another element at the boundaries between the KNN nanocolumns to form a perovskite derivative structure. Specifically, the nanostructured KNN-based thin film consists of perovskite KNN nanocolumns that are interspersed with Mn-inlaid antiphase boundaries. Atomic resolution images revealed that the thickness of perovskite KNN slabs varied from a few to tens of nanometers, while the coherent antiphase boundaries consisted of one or two atomic layers enriched with Mn. This strategic incorporation of Mn not only helped to balance the charges originating from alkali ions deficiency, leading to a reduced leakage current but also induced a noticeable out-of-plane tensile strain in the KNN nanocolumns. This strain promoted a high degree of tetragonality, resulting in an improvement in its ferroelectric polarization with a high twice-remanent polarization value of ~114\u2009\u03bcC/cm2 under an applied electric field of 606\u2009kV/cm.",
            "section_image": []
        },
        {
            "section_name": "Results and discussion",
            "section_text": "A ceramic target of K0.5Na0.5NbO3 with 2\u2009wt% MnO2 addition (KNN-M) was used for the deposition of KNN-M films on La0.07Sr0.93SnO3 (LSSO)-coated SrTiO3 (STO) (001) substrates via pulsed laser deposition (PLD) method. High-resolution X-ray diffraction (HRXRD) techniques were employed to assess the crystalline quality of the KNN-M films. Figure\u00a01a shows the XRD 2\u03b8-\u03c9 pattern of a representative KNN-M film. Only (00\u2009l) (l\u2009=\u20091, 2, 3) reflection peaks of KNN-M, LSSO and STO are observed, indicating that the film is epitaxially grown along the c-axis direction with a single phase. The rocking curves shown in Fig.\u00a01b exhibit a full-width-at-half-maximum of approximately 0.18\u00b0 for KNN-M (002) and 0.09\u00b0 for LSSO (002), demonstrating a high crystallinity of the films. To examine the epitaxial relationship and the strain state of the samples, the X-ray reciprocal space mappings (RSMs) around the symmetric (002) and asymmetric (\\(\\bar{1}\\)30) reflections of the film are measured in Fig.\u00a01c and d, respectively. The discrete and clear spots in Fig.\u00a01c and d confirm the orientation relationship between the films and STO substrate. In Fig.\u00a01d, the Qx value of the KNN-M (\\(\\bar{1}\\)30) spot obviously deviates from that of STO and LSSO, suggesting a relaxation of the lattice mismatch strain between the film and substrate. Based on the RSM results, the out-of-plane and in-plane lattice parameters of the KNN-M films were calculated to be 4.02\u2009\u00c5 and 3.95\u2009\u00c5, respectively.\n\na\u2013d The XRD 2\u03b8-\u03c9 pattern, rocking curves around STO (002), LSSO (002) and KNN-M (002) and RSMs around the STO (002) and (\\(\\bar{1}\\)03) reflections. e\u2013g The cross-sectional low magnification HAADF image, SAED pattern and atomic resolution HAADF image of the KNN-M thin film. The red triangle (g) points towards the antiphase boundaries and the red rectangular box (g) represents the overlap of the KNN nanocolumns. h, i The planar-view low-magnification ABF image and corresponding EDS mapping of Mn element for the KNN-M thin film, where the Mn enrichment can be observed at the antiphase boundaries. j The planar-view atomic resolution HAADF image of the KNN-M thin film. The yellow and red frame (j) represented the antiphase boundaries and transition dislocation, respectively. The APB in this figure represents antiphase boundaries.\n\nFigure\u00a01e displays a high-angle annular dark field (HAADF) scanning transmission electron microscopy (STEM) image of the KNN-M film along the [010] zone axis. It is evident that the KNN-M thin film consists of vertically aligned nanocolumns in the out-of-plane direction rather than a homogeneous and smooth cross-section. The X-ray energy dispersive spectroscopy (EDS) analysis confirms the presence of Mn enrichment at the column boundaries along the out-of-plane direction, as seen in Supplementary Fig.\u00a01. Additionally, the selected area electron diffraction (SAED) pattern of the KNN-M thin films along the [010] zone axis, as shown in Fig.\u00a01f, reveals the classic single crystal diffraction spots in the out-of-plane direction, while the streaks along the in-plane direction are attributed to the shape effect. This effect arises from the principle that a small thickness in real space corresponds to a large length in reciprocal space, and vice versa. Thus, the reciprocal diffraction pattern further supports the presence of nanocolumns in the specimens, which is consistent with the HAADF image in real space. Atomic resolution HAADF images reveal a series of nanocolumn grains exhibiting the classic single crystal phase perovskite structure, as shown in Fig.\u00a01g. However, it is observed that the lattices of neighboring perovskite KNN nanocolumns undergo a relative shift by half a unit cell length at the phase boundaries along the out-of-plane direction, indicated by the red triangle in Fig. 1g.\n\nDue to the overlap of the nanocolumnar structure in the cross-sectional observation direction, indicated by the red rectangle in Fig.\u00a01g and Supplementary Fig.\u00a02, we studied the microstructure using a plan-view sample without the substrate. We found that the KNN-M films present the \u2018Tetris-like\u2019 microstructure consisting of dense nanocolumns with sizes ranging from a few to tens of nanometers. Through annular bright field (ABF) imaging, we observed that the nanocolumns predominantly exhibit atomic-scale linear dark contrast along both the [001] and [010] directions, as shown in Fig.\u00a01h and Supplementary Fig.\u00a03. The corresponding EDS composition analysis reveals that the nanocolumn areas are composed of K, Na, Mn, Nb and O elements, with apparent Mn enrichment observed in some linear dark contrast areas, as shown in Fig.\u00a01i and Supplementary Fig.\u00a04. The electron energy loss spectroscopy (EELS) analysis indicates that the Mn ions mainly exhibit bivalence (Mn2+) (Supplementary Fig.\u00a05). In addition, the atomic resolution HAADF imaging reveal that the lattices of adjacent perovskite KNN nanocolumns are coherent, but undergo a half-unit cell shift relative to each other across the atomic-scale antiphase boundaries with Mn enrichment, as marked within the yellow rectangle in Fig.\u00a01j. At the ends of these antiphase boundaries, the lattice misregistry of 1/2 unit cell is gradually reduced to zero with continuous atom deficiency along the boundaries and no more Mn element could be detected with EDS analysis, as shown in the red rectangles in Fig.\u00a01j and Supplementary Fig.\u00a06.\n\nFurthermore, we have identified two different atomic configurations for the Mn-inlaid antiphase boundaries, as illustrated in Fig.\u00a02. Figure\u00a02a displays an atomic resolution HAADF image of one type of antiphase boundary structure (referred to as Type-I). In this image, a coherent antiphase feature is observed, where the A-site lattice of one KNN nanocolumn runs into the B-site lattice of the neighboring nanocolumn across a single atomic column. This single atomic column exhibits a brighter contrast than the A-site K/Na atomic columns, but a darker contrast compared to the B-site Nb/O atom columns. The line-scans of image intensity were performed along the single atomic column layer. The line profile of intensity reveals similar atomic column intensities, as shown in Fig.\u00a02b. Based on the uniform image contrasts and corresponding line profiles, it can be inferred that the atomic columns in the Type-I antiphase boundaries have similar chemical compositions. The intensity of the atomic column in HAADF image is approximately proportional to the square of the atomic number (Z2)27, making the HAADF images suitable for composition analysis. However, due to the much smaller scattering cross-section of oxygen, the light element oxygen cannot be observed in the HAADF image. Therefore, we also obtained atomic resolution integrated differential phase contrast (iDPC) images to visualize the distribution of all atoms, as shown in Fig.\u00a02c. The iDPC image reveals only one atomic column at the antiphase boundary, and no separate oxygen atom columns are observed in the plan-view direction. In addition, we observed that the single atomic layer at the antiphase boundaries can gradually translate to a Ruddlesden-Popper like double atomic layer with in-situ beam irradiation in STEM mode, and vice versa (Fig.\u00a02d, Supplementary Figs.\u00a07 and 8).\n\na In-plane atomic resolution HAADF image of the Type-I antiphase boundaries. The red frames in (a) indicate the unit cells of KNN-M near the antiphase boundary, where 1/2 unit cell shift was observed along the boundary. b Line-profile of the single antiphase atomic columns along the antiphase boundary in (a). c The iDPC image of the Type-I antiphase boundaries. Here, only one atomic column at the antiphase boundary can be observed (yellow rectangle frame). d The HAADF image of Type-I antiphase boundaries with in-situ electron irradiations. e\u2013j In-plane HAADF image of the KNN-M thin film containing Type-I antiphase boundaries and corresponding EDS mapping of the K, Na, O, Mn and Nb elements, respectively. k Composite elemental map with Nb (in blue) and Mn (in yellow), where the Mn occupation at the A-site of KNN perovskite structure is directly observed. l Schematic structural model of the Type-I Mn-inlaid antiphase boundaries. It indicates that the single atom column at the Type-I boundary is mainly composed of Mn and O elements. m In-plane atomic resolution HAADF image of the Type-II antiphase boundaries. The red frames in (m) indicate the unit cells of KNN-M near the Type-II antiphase boundary, where 1/2 unit cell shift was observed along the boundary. n Line-profile of the single antiphase atomic columns along the transition boundary in (m). o The iDPC image of the Type-II antiphase boundaries. Here, the double atomic column at the antiphase boundary can be observed (yellow rectangle frame). p Schematic structural model of Type-II antiphase boundaries.\n\nWe performed the EDS mapping to study the atomic resolution composition distribution in Type-I antiphase boundary regions, as shown in Fig.\u00a02e. The color-coded elemental maps of K, Na, O, Mn and Nb are presented in Fig.\u00a02f\u2013j, respectively. It is evident that all the elements are generally distributed uniformly in the KNN-based nanocolumns. However, the atomic columns at the antiphase boundary layer are primarily composed of the Mn and O elements, with a trace amount of K/Na. The composite map of Nb/Mn in Fig.\u00a02k illustrates the relative positions of the Nb and Mn atoms. Based on the elemental distribution maps, we find that the Mn element occupies the A-site of the perovskite lattice. The theoretical bond valence model study also indicated that the substitution of Mn in A-site was more energy stable than B-site, according to the global instability index calculated using Structure Prediction Diagnostic Software28,29, as shown in Supplementary Figs.\u00a09 and 10. Due to the structural changes at the boundaries during in-situ beam irradiation, as shown in Fig.\u00a02d and Supplementary Fig.\u00a07, the Mn enrichment is observed along the boundary, but the location of Mn signals at the antiphase boundaries does not precisely correspond to the atomic-scale image from the EDS analysis. By analyzing the atomic resolution images in both the planar-view and cross-sectional directions (Supplementary Fig.\u00a02) and conducting composition analysis, we have depicted the schematic structure of Type-I antiphase boundaries in Fig.\u00a02l. This structure consists of nanocolumnar perovskite KNN sheets alternating with a single Mn/O sheet running along the c axis direction and the neighboring perovskite slabs relatively shifting by half a unit cell length in both the in-plane and out-of-plane directions. At Type-I antiphase boundaries, the lattice site corresponds to the A-site of one KNN nanocolumn and the O-site of another KNN nanocolumn. Therefore, both the Mn and O atoms can randomly occupy the atom site at the boundaries theoretically.\n\nThe other antiphase boundary (Type-II) is illustrated in Fig.\u00a02m, where the two adjacent KNN phases coherently transit across a double atom layer, and the distance between the neighboring Nb atomic columns at the boundaries is approximately 3/2-unit cells. We observed distinct contrast variations for the atom columns at the transition layers, which differ from the uniform contrast of the atom columns at Type-I antiphase boundaries. The line profile of intensity also exhibits a noticeable difference for the atomic column along one row of transition atomic columns in Fig.\u00a02m, as shown in Fig.\u00a02n. The observed variations in image contrast or line profiles can be attributed to composition differences in each atomic column at Type-II antiphase boundaries. Through atomic resolution composition analysis, we determined that the atom columns with bright contrast primarily consist of Nb atoms, while the dark atom columns are composed of K/Na/Mn (Supplementary Fig.\u00a011). Additionally, we also observed the presence of Mn enrichment at the boundaries. However, the signals are noticeably weaker compared to the distinct single Mn-rich layer observed at Type-I antiphase boundaries (Supplementary Fig.\u00a012). We also acquired the iDPC images for Type-II antiphase boundaries (Fig.\u00a02o), which reveal separated O atom columns that can bond with neighboring Nb atoms to form oxygen octahedra at the boundaries. Furthermore, we found that Type-II antiphase boundaries remained stable under beam irradiation. Based on the aforementioned experimental results, we constructed the schematic structural model of Type-II antiphase boundaries, as depicted in Fig.\u00a02p. For comparison, we also prepared the pure KNN thin films with a similar deposition process. From the cross-sectional view, serials of nanocolumns can also be observed (Supplementary Fig.\u00a013a). Atomic resolution HAADF images revealed no noticeable lattice shifts between two adjacent nanocolumns in the out-of-plane direction (Supplementary Fig.\u00a013b). However, the plan-view image displayed a high density of stacking faults due to the K/Na deficiency (Supplementary Fig.\u00a013c). This deficiency resulted in a high leakage current and prevented the display of ferroelectricity at room temperature12,14.\n\nWe examined the ferroelectric polarization of this film and found that the out-of-plane phase image of the as-grown film without dc bias exhibits homogeneity across the layer with a weak contrast, as shown in Fig.\u00a03a, indicating an ordered out-of-plane polarization component. This result is also attested to the excellent epitaxial quality of the films. The out-of-plane piezoelectric force microscope (PFM) phase can switch to the opposite direction under a voltage of \u22128 V. When a positive dc bias of +8\u2009V was applied, the PFM phase switched to the same direction as the as-grown film, which confirms that the out-of-plane polarization is directed uniformly toward the bottom of the film. The well-saturated ferroelectric polarization-electric field (P\u2013E) hysteresis loops of the KNN-M film were displayed at room temperature (Fig.\u00a03b). The film demonstrated a enhancement in remanent polarization (Pr) with the 2Pr value of ~114\u2009\u03bcC/cm2 when subjected to an applied electric field of 606\u2009kV/cm. The 2Pr value of the KNN-M thin film is larger than the values so far reported for KNN-based films (7.1\u221264.9\u2009\u03bcC/cm2), and comparable to that of typical PZT ferroelectric thin films24. Furthermore, at the temperature of 80\u2009K, no significant variation in Pr was observed, but the breakdown field strength increased to 2700\u2009kV/cm, as shown in Fig.\u00a03c. Supplementary Fig.\u00a014 shows the temperature-dependent ferroelectric behaviors of the KNN-M film, where well-defined P\u2013E hysteresis loops from 25\u2009\u00b0C to 200\u2009\u00b0C were obtained. Additionally, the polarization of the films with different switching cycles for the KNN-M film measured at 10\u2009kHz with an applied electric field of 200\u2009kV/cm is shown in Fig.\u00a03d, the inset shows the P\u2013E hysteresis loops before and after fatigue. It can be seen that the KNN-M film did not show a noticeable attenuation of the P\u2013E hysteresis loops until 107 switching cycles.\n\na The out-of-plane polarization switching of the KNN-M film captured using PFM imaging technique under a dc bias of \u00b1 8\u2009V. b Room-temperature P\u2013E hysteresis loops displayed under different electric fields. c The P\u2013E hysteresis loops under different electric field for the KNN-M thin films at a low-temperature of 80\u2009K. d Polarization fatigue performance (normalized \u00b1 Pr vs the number of switching cycles) for the KNN-M film measured at 10\u2009kHz with an applied electric field of 200\u2009kV/cm, the inset shows the P\u2013E hysteresis loops before and after fatigue.",
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        {
            "section_name": "Discussion",
            "section_text": "Based on the microstructure analysis and the ferroelectric properties, we delve into the mechanisms behind the formation of a nanocolumnar structure with Mn-inlaid antiphase boundaries and the enhancement of ferroelectric polarization. In the case of pure KNN thin films, the appropriate deposition process led to the formation of vertical nanocolumnar structures aligned along the out-of-plane direction. Through atomic resolution investigation of microstructure, it was observed that the KNN nanocolumns maintained the normal perovskite structure. Significant K/Na deficiencies primarily occurred at the boundaries, resulting in lattice rearrangement and the formation of charged out-of-phase boundaries. These crystallographic out-of-phase boundaries, commonly found in epitaxial perovskite films, tend to propagate throughout the entire thickness of the film. Consequently, nanocolumnar KNN thin films exhibited large leakage currents, as depicted in Supplementary Fig.\u00a015 and ref.12. However, consistent with previous studies11,16,19, our experimental results show that the addition of a small concentration of Mn into KNN film was very effective in reducing the leakage current density. According to the above atomic structure imaging and composition analysis, it is assumed that Mn ions mainly fill and compensate A-site vacancies formed by the volatilization of K+/Na+ ions. Due to the small number of A-site K+/Na+ vacancies in the KNN nanocolumns and the significantly smaller radius of the Mn ion than that of A-site K+/Na+ ions, the Mn doping contents is low in the lattice of KNN nanocolumns. In addition, considering its primary valence, Mn2+ can act as a donor-dopant on the A-site of the perovskite lattice. However, in order to balance the charge, the occupancy of Mn2+ on the A-site vacancies was only partial. As a result, partial A-site deficiency still existed in the KNN nanocolumns18. On the contrary, the serious K/Na volatilizations lead to the high-density A-site vacancies at the boundaries. This means that the Mn has more opportunities to fill the A-site vacancies. Therefore, a high density of Mn was accumulated at the phase boundaries to form the atomic-scale Mn-rich boundaries.\n\nIn the case of Type-I antiphase boundaries, both cation Mn2+ and anion O2- can occupy the atomic site at the single antiphase boundary layer. By adjusting the ratio of Mn/O, we can achieve charge balance in optimum experimental conditions (Supplementary Fig.\u00a016). For Type-II antiphase boundaries, which resemble the Ruddlesden-Popper structure, separate atomic columns of cations and anion O2- were observed. The cation atomic sites at these boundaries can be occupied by the Nb5+, Mn2+, K+ and Na+ ions. The ratios among these four cations could also be adjusted experimentally to maintain charge balance (Supplementary Fig.\u00a017). Consequently, the leakage currents can be significantly reduced, which is crucial for the ferroelectric functionality of the thin film. In our study, we also investigated the microstructure of KNN thin films with the Mn concentration of 1\u2009wt% and 5\u2009wt%. It was observed that the sample with a low Mn doping content, such as 1\u2009wt%, exhibited a vertical nanocolumns structure, but the K/Na deficiencies were not fully compensated (Supplementary Fig.\u00a018). As the Mn doping level increased to 5\u2009wt%, the nanoscale Mn enriched phases were observed, which disrupted the epitaxial growth of the thin films, as shown in Supplementary Fig.\u00a019. Furthermore, we studied the room-temperature P\u2013E hysteresis loops of the KNN thin films samples with the Mn doping concentration of 0, 0.7, 1, 1.5, 3, and 5\u2009wt% as shown in Supplementary Fig.\u00a020. High leakage current and low remanent polarization were observed in the pure KNN thin films. The remanent polarization gradually increased and the leakage current decreased as the Mn doping concentration increased. However, the apparent high leakage current and the poor remanent polarization are again visible in the larger 3 and 5\u2009wt% Mn doping samples. More importantly, the specific atomic configurations of the Mn-inlaid antiphase boundaries induced apparent lattice strains, as evidenced by the annular dark field (ADF) images (Supplementary Fig.\u00a021, Supplementary Fig.\u00a022), where the brighter image contrast in ADF image suggests the existence of lattice strains27. Different from the conventional in-plane heteroepitaxial interfacial strain that gradually relax in nanoscale with the growth of KNN thin films20, the high-density boundaries are organized in an ordered manner on a nanoscale and extend vertically throughout the KNN-M thin films. As a result, the apparent strain can be experienced through the entire thin film.\n\nHere, the intuitive evolution of lattice parameters was studied using the geometry phase analysis method. Figure\u00a04a displays an ADF image of the KNN-M thin film, revealing the presence of two types of boundaries. The corresponding relative lattice strain are plotted in Fig.\u00a04b (Exx), Fig.\u00a04c (Eyy) and Fig.\u00a04d (Exy), respectively. The Exx, Eyy and Exy are relative values representing local lattice displacements from the referenced KNN lattice in horizontal, vertical, and shear directions in Fig.\u00a04a. The positive or negative value of E indicates the measured local lattice parameters being larger or smaller than the reference one, respectively. It can be seen that the boundaries exhibit apparent relative lattice strains, mainly perpendicular to their orientation, with no observable shear strain and the relative strains parallel to the boundaries as shown in Fig.\u00a04b\u2013d and Supplementary Fig.\u00a023. The local areas with dark contrast can be observed at the antiphase boundaries in Fig.\u00a04b c, which attributed to atomic structure transition of the single atomic layer to the Ruddlesden-Popper like double atomic layer at the antiphase boundaries with the beam irradiation shown in Fig.\u00a02d and Supplementary Fig.\u00a024. It is well-known that lattice strain can significantly influence the ferroelectric polarization of thin films. The displacement of the center polar B-site cations relative to the corner A-site cations (\u03b4B-A) was used as a measure of the local polarization. Figure\u00a04e displays a colored arrow map of \u03b4B-A, representing the orientation and magnitude of the polarization. In general, the film exhibited apparent displacement polarization, with the larger polarization observed near the boundaries. The different strains presented at each type of boundary resulted in the formation of multidomain structures with a mixture of various orientations of polarization. To investigate the impact of boundary strain on ferroelectric polarization, we conducted phase field simulations. The phenomenological model and relative lattice strain distributions used in these simulations were obtained from Fig.\u00a04a\u2013d, as shown in Supplementary Fig.\u00a025. Specifically, we examined the different lattice strains, namely \u03b5local (0, 0.1, and 0.2), induced by the Mn accumulated boundaries, to elucidate their effects. Our simulations employed the orthorhombic phase with the [110]-oriented polarization of KNN at room temperature16,30, as illustrated in Supplementary Fig.\u00a026, which shows the detailed microstructural evolution. As the applied external electric field increased, the polarizations transitioned from the orthorhombic phase (represented by different colors in Fig.\u00a04f) to the tetragonal phase (indicated by light blue color in Fig.\u00a04g). Importantly, the lattice strains around the boundaries induced larger polarization in both in-plane and out-of-plane directions, as shown in Fig.\u00a04f and Supplementary Figs.\u00a026 and 27. Therefore, the simulated ferroelectric loop demonstrated an increased ferroelectric polarization with the increase of lattice strain (Fig.\u00a04h). Moreover, the local strain field stabilized the tetragonal phase. Thus, the tetragonal phase domains become more stable with an increase in the strain field (see Supplementary Fig.\u00a027). It becomes more difficult to switch the stabilized domains when changing the external electric field, which increases the coercive electric field strength.\n\na In-plane atomic-resolution ADF image of the KNN-M thin film. b\u2013d Maps depicting the relative lattice strains: (b) Exx (in-plane strain), (c) Eyy (out-of-plane strain) and (d) Exy (shear strain). e Colored arrows map of polarizations (\u03b4Nb-K/Na), indicating the polarization orientation of the KNN nanocolumns in (a). f Polarization of KNN-M obtained from phase-field simulation. g Mapping of the piezoelectric response of the KNN-M film under an applied electric field obtained from phase-field simulation. h Calculated P\u2013E curves with different local strains.\n\nIn summary, we prepared and observed the Mn-inlaid antiphase boundaries structure in perovskites. The high-density vertical Mn-inlaid antiphase boundaries show the positivity effect on charge balance, coherent transition to the neighboring KNN nanocolumns and the induction of large strain for the nanocolumnar KNN lattice in the entire KNN-M thin films. Therefore, higher ferroelectric polarizations have been observed for the KNN-based thin films. The Mn-inlaid antiphase boundaries also give a possible structure frame to modulate the various properties of perovskites.",
            "section_image": [
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        },
        {
            "section_name": "Methods",
            "section_text": "The ceramic targets of the (K,Na)NbO3 with 0/0.75/1/2/5\u2009wt% MnO2 were fabricated using the conventional solid-state reaction method. High-purity materials, including K2CO3 (99.0%), Na2CO3 (99.8%), Nb2O5 (99.9%) and MnO2 (98.8%), were obtained from Sinopharm Chemical Reagent Beijing Co. Ltd. Initially, the raw materials were accurately weighed according to the stoichiometric ratio of (K0.5Na0.5)NbO3 and then homogenized in a planetary mill for 24\u2009h using ethyl alcohol as the medium. After calcination at 750\u00b0C for 4\u2009h, the resulting powder mixtures were milled, dried, and sieved. Subsequently, additional MnO2 was incorporated into the powders and homogenized for another 24\u2009h in the planetary mill. The resulting powder mixtures were then dried and sieved. Next, the mixed KNN-M powders were compacted into disks by uniaxial pressing at a pressure of 150\u2009MPa for 2\u2009min. Finally, the KNN-M pellets, with a diameter of 25\u2009mm, were sintered at 1120\u2009\u00b0C for 4\u2009h to prepare the ceramic targets.\n\nThe KNN-M films were deposited on the STO (001) substrate buffered with LSSO layer using the PLD technique with a 248\u2009nm KrF excimer laser. The deposition process involved maintaining the substrate temperature at 735\u2009\u00b0C and the O2 pressure at 15\u2009Pa for the LSSO layer, followed by deposition of the KNN-M films at 700\u2009\u00b0C and 30\u2009Pa. The target-substrate distance was set as 5\u2009cm, and the laser energy were kept at 2\u2009J/cm2. The thicknesses of the KNN-M and LSSO were approximately 300\u2009nm and 30\u2009nm, respectively. After deposition, each film underwent in-situ annealing for 15\u2009minutes before being cooled down to room temperature.\n\nThe crystalline phase of films was characterized by HRXRD using Cu K\u03b11 radiation. The samples were mounted in the diffractometer (PANalytical, X\u2019Pert), for linear scans, rocking curves and RSMs at room temperature.\n\nThe cross-sectional TEM samples were prepared using a focused ion beam (FIB) method (Thermofisher Helios UX5, USA). For the plan-view TEM samples, we mechanically polished the samples to a thickness of approximately 3\u2009\u03bcm using the tripod method (ALLIED Multiprep) and then ion-mill the samples to tens of nanometers using FIB methods (Thermofisher Helios UX5, USA). TEM characterizations, low magnification STEM imaging, and nanoscale EDS composition analysis were performed using the Thermofisher Talos F200X equipped Four (Si-Li) EDS detectors with the accelerating voltage of 200\u2009kV, where the acquiring times about 30\u2009mins were used for each nanoscale EDS mapping. Atomic resolution HAADF and iDPC images were acquired using the Thermofisher Titan Themis Z with an accelerating voltage of 300\u2009kV. Atom resolution ADF image and EDS mapping were obtained using the Thermofisher Titan cubed Themis G2 300 with the accelerating voltage of 300\u2009kV. In experiment, we consecutively acquired 20 frames drift-corrected atomic resolution ADF images, and stacked them for atom displacement polarizations analysis and geometry phase analysis. For atomic resolution EDS mapping, we firstly adjust the experimental conditions of the zone axis [100] of target sample area, beam current (0.1\u2009nA), accelerating voltage (300\u2009kV), etc. and then wait for about 16\u2009h to ensure the stable of TEM sample and microscopy. It takes about 40\u2009min to acquire each atomic resolution EDS mapping with 512\u2009*\u2009512 pixels and 10 dell times. The acquisition of EELS data was carried out using Gatan electron energy loss spectroscopy (EELS) on the FEI Titan G2 80\u2013300 with an accelerating voltage of 300\u2009kV.\n\nPolarization versus electric field (P\u2013E) hysteresis loops were measured through the ferroelectric test system (TF Analyzer 2000E, Germany) at 1\u2009kHz at room temperature. The P\u2013E loops at liquid nitrogen temperature of 80\u2009K were obtained with Cryogenic Probe Station supplied by Lake Shore Company. The ferroelectric domains and polarization reversal behaviors were characterized by piezoresponse force microscopy (PFM, Asylum Cypher), where the chemical mechanical polishing technology was used to decrease the surface roughness of thin films. Here, the non-crystallizing 0.05 micron colloidal silica suspension was used for the surface polishing of thin films about 3\u2009min on the ALLIED Multiprep\u2122 System with 5 revolutions per minute. Subsequently, the ethyl alcohol and acetone were used for the ultrasonic cleaning of the thin films, successively.\n\nA standard peak finding algorithm is employed for the ADF image, which is based on fitting two-dimensional Gaussian functions to the intensity maxima. This algorithm allows us to determine the position and brightness of each column. Using these data, we can calculate the off-center ion displacements between the Nb column and the center of the unit cell. The center of the unit cell is determined by the average coordinate of the four K/Na atomic columns. We use the following formula to calculate the displacements:\n\nwhere i/j indicate the row/column number of each atom column, rij indicates the position of Nb atomic columns, and Rij indicates the position of K/Na atomic columns.\n\nA single crystal considering Cubic (C) to Orthorhombic (O) ferroelectric transition with Mn-inlaid antiphase boundaries has been carried out in phase-field simulations. The total free energy of the ferroelectric system can be described as:\n\nwhere f bulk represents the bulk free energy density,\n\nwhere \\({\\alpha }_{ij}\\) is the coefficient and depends on concentration c and temperature T.\n\nfgrad represents the gradient energy density,\n\nwhere G11 is the gradient energy coefficient.\n\nfcouple represents the couple effect caused by lattice strain \u03b5local.\n\nwhere \\({q}_{11}={C}_{11}{Q}_{11}+2{C}_{12}{Q}_{12}\\), \\({q}_{12}={C}_{11}{Q}_{12}+{C}_{12}({Q}_{11}+{Q}_{12})\\), \\({q}_{44}=2{C}_{44}{Q}_{44}\\),C11, C12, and C44 is the elastic constants in Voigt\u2019s notation and Qij is the electrostrictive coefficients. felas is the long-range elastic interaction energy densities and felec is the electrostatic interaction energy densities.\n\nwhere cijkl is the elastic constant tensor, \u03b5ij the total strain, \u03b50kl the electrostrictive stress-free strain, i.e., \u03b50kl =QijklPkPl.\n\nwhere fdipole is the dipole-dipole interaction caused by polarization, fdepola the depolarization energy density and fappl the energy density caused by applied electric field. The dimensionless parameters used in our simulations:\n\nC11\u2009=\u20091780, C12\u2009=\u2009964, C44\u2009=\u20091220, Q11\u2009=\u20090.1, Q12\u2009=\u2009\u22120.034, Q44\u2009=\u20090.029.\n\nThe temporal evolution of the spontaneous polarization field can be obtained by solving the time dependent Ginzburg Landau (TDGL) equation:\n\nwhere M is the kinetic coefficient, F is the total free energy, and t is time.",
            "section_image": []
        },
        {
            "section_name": "Data availability",
            "section_text": "All data supporting the findings are provided as figures in the article and Supplementary Information. All raw data generated during the current study are available from the corresponding author upon request.\u00a0Source data are provided with this paper.",
            "section_image": []
        },
        {
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            "section_image": []
        },
        {
            "section_name": "Acknowledgements",
            "section_text": "This research was supported by the National Natural Science Foundation of China (Grant No. 51702253) (Z.Y.), (Grant No. 12374095, 11574324) (F.C.), (Grant No. 12204005) (L.X.), the Natural Sciences & Engineering Research Council of Canada (NSERC DG, RGPIN-2023-04416) (Z.Y.), the Natural Science Foundation of Shaanxi Province (grant 2022JQ-325) (C.L.). We also thank helpful discussions and suggestions with C.L. Jia, X.B. Yang, D.M Xu and Y. Chao.",
            "section_image": []
        },
        {
            "section_name": "Author information",
            "section_text": "Instrumental Analysis Center, Xi\u2019an Jiaotong University, Xi\u2019an, China\n\nChao Li\u00a0&\u00a0Chuansheng Ma\n\nElectronic Materials Research Laboratory, Key Laboratory of the Ministry of Education, School of Electronic Science and Engineering, Xi\u2019an Jiaotong University, Xi\u2019an, China\n\nLingyan Wang,\u00a0Xuerong Ren,\u00a0Yijun Zhang,\u00a0Guohua Dong,\u00a0Haixia Liu,\u00a0Xiaoyong Wei\u00a0&\u00a0Wei Ren\n\nInformation Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, Hefei, China\n\nLiqiang Xu\n\nResearch Center for Advanced Functional Ceramics, Wuzhen Laboratory, Jiaxing, China\n\nFangzhou Yao\u00a0&\u00a0Ke Wang\n\nSchool of Physics and Information Technology, Shaanxi Normal University, Xi\u2019an, China\n\nJiangbo Lu\u00a0&\u00a0Hongmei Jing\n\nFrontier Institute of Science and Technology, Xi\u2019an Jiaotong University, Xi\u2019an, China\n\nDong Wang\n\nSchool of Chemistry, Xi\u2019an Jiaotong University, Xi\u2019an, China\n\nZhongshuai Liang\n\nLaboratory for Complex, Collective and Critical phenomena (L3C), State Key Laboratory for Mechanical Behavior of Materials, Xi\u2019an Jiaotong University, Xi\u2019an, China\n\nPing Huang\n\nSchool of Materials Science and Engineering, Peking University, Beijing, China\n\nShengqiang Wu\n\nThe State Key Laboratory of Materials-Oriented Chemical Engineering, College of Materials Science and Engineering, Nanjing Tech University, Nanjing, China\n\nYinong Lyu\n\nDepartment of Chemistry & 4D LABS, Simon Fraser University, Burnaby, B.C., Canada\n\nZuo-Guang Ye\n\nAnhui Province Key Laboratory of Low-Energy Quantum Materials and Devices, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, China\n\nFeng Chen\n\nSearch author on:PubMed\u00a0Google Scholar\n\nSearch author on:PubMed\u00a0Google Scholar\n\nSearch author on:PubMed\u00a0Google Scholar\n\nSearch author on:PubMed\u00a0Google Scholar\n\nSearch author on:PubMed\u00a0Google Scholar\n\nSearch author on:PubMed\u00a0Google Scholar\n\nSearch author on:PubMed\u00a0Google Scholar\n\nSearch author on:PubMed\u00a0Google Scholar\n\nSearch author on:PubMed\u00a0Google Scholar\n\nSearch author on:PubMed\u00a0Google Scholar\n\nSearch author on:PubMed\u00a0Google Scholar\n\nSearch author on:PubMed\u00a0Google Scholar\n\nSearch author on:PubMed\u00a0Google Scholar\n\nSearch author on:PubMed\u00a0Google Scholar\n\nSearch author on:PubMed\u00a0Google Scholar\n\nSearch author on:PubMed\u00a0Google Scholar\n\nSearch author on:PubMed\u00a0Google Scholar\n\nSearch author on:PubMed\u00a0Google Scholar\n\nSearch author on:PubMed\u00a0Google Scholar\n\nSearch author on:PubMed\u00a0Google Scholar\n\nSearch author on:PubMed\u00a0Google Scholar\n\nC.L., L.X., F.C., and L.W. conceived and designed the study; F.Y. and K.W. fabricated the ceramic targets; L.X. and F.C. prepared the thin films; L.X., Z.L., L.W., and C.L. carried out the electric testing; G.D., H.L., and C.L. carried out the PFM testing; L.X. and Z.L. performed X-ray diffraction and analyzed the data; C.L. prepared the TEM samples and performed S/TEM and analyzed the data. H.J., S.W, P.H., and C.L. performed aberration-corrected STEM images and analyzed the data; J.L. and C.L. performed atomic resolution EDS mapping and analyzed the data; C.L., C.M., S.W., and Y.L. performed EELS; D.W. performed and analyzed the phase-field simulations; C.L., L.X., L.W., F.C., X.W., W.R., Y.Z., and Z.-G.Y. wrote and modified the manuscript; All authors discussed the results and revised the manuscript.\n\nCorrespondence to\n                Lingyan Wang, Liqiang Xu or Feng Chen.",
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            "section_text": "Li, C., Wang, L., Xu, L. et al. Mn-inlaid antiphase boundaries in perovskite structure.\n                    Nat Commun 15, 6735 (2024). https://doi.org/10.1038/s41467-024-51024-2\n\nDownload citation\n\nReceived: 21 January 2024\n\nAccepted: 23 July 2024\n\nPublished: 07 August 2024\n\nVersion of record: 07 August 2024\n\nDOI: https://doi.org/10.1038/s41467-024-51024-2\n\nAnyone you share the following link with will be able to read this content:\n\nSorry, a shareable link is not currently available for this article.\n\n\n\n\n                            Provided by the Springer Nature SharedIt content-sharing initiative\n                        ",
            "section_image": [
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        {
            "section_name": "Associated content",
            "section_text": "Collection",
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        }
    ],
    "supplementary_files": [
        {
            "title": "SupplementaryInformation2.pdf",
            "link": "https://assets-eu.researchsquare.com/files/rs-3884985/v1/53b8864822df5bb4e615a5ef.pdf"
        }
    ]
}