Sn-modified BaTiO3 thin film with enhanced polarization
Sn-modified BaTiO3 thin film with enhanced polarization
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DOI：
10.1116/6.0002208
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发表时间：
2023-03
期刊：
影响因子：
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通讯作者：
William T. Nunn;Abinash Kumar;R. Zu;Bailey R. Nebgen;Shukai Yu;Anusha Kamath Manjeshwar;V. Gopalan;J. Lebeau;R. James;B. Jalan
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文献类型：
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作者：
William T. Nunn;Abinash Kumar;R. Zu;Bailey R. Nebgen;Shukai Yu;Anusha Kamath Manjeshwar;V. Gopalan;J. Lebeau;R. James;B. Jalan
Sn 改性 BaTiO3 薄膜的混合分子束外延 (MBE) 生长在整个成分空间中实现了不同的域结构和晶体对称性。结合光学二次谐波发生（SHG）偏振测定法和扫描透射电子显微镜（STEM）来确定这些薄膜的宏观和微观结构以及晶体对称性。 SHG 旋光测量揭示了薄膜整体晶体对称性的变化，从四方晶系 ( P4 mm) 到立方晶系 [公式：参见文本]，在 BaTi1− xSn xO3 (BTSO) 中，x = 0 到 1。 STEM 成像显示，当 Sn 含量较低 ( x = 0.09) 时观察到的长程极性顺序随着 Sn 含量增加 ( x = 0.48) 转变为短程极性顺序。与 STEM 的原子位移测量一致，通过 SHG 测定，Sn 改性 BaTiO3 中的最低 Sn 含量 x = 0.09 时获得最大极化。这些结果与最近的块状陶瓷报告一致，并进一步确定该材料系统作为含铅弛豫薄膜器件的潜在替代品。
Hybrid molecular beam epitaxy (MBE) growth of Sn-modified BaTiO3 films was realized with varying domain structures and crystal symmetries across the entire composition space. Macroscopic and microscopic structures and the crystal symmetry of these thin films were determined using a combination of optical second harmonic generation (SHG) polarimetry and scanning transmission electron microscopy (STEM). SHG polarimetry revealed a variation in the global crystal symmetry of the films from tetragonal ( P4 mm) to cubic [Formula: see text] across the composition range, x = 0 to 1 in BaTi1− xSn xO3 (BTSO). STEM imaging shows that the long-range polar order observed when the Sn content is low ( x = 0.09) transformed to a short-range polar order as the Sn content increased ( x = 0.48). Consistent with atomic displacement measurements from STEM, the largest polarization was obtained at the lowest Sn content of x = 0.09 in Sn-modified BaTiO3 as determined by SHG. These results agree with recent bulk ceramic reports and further identify this material system as a potential replacement for Pb-containing relaxor-based thin film devices.