Abstract Lanthanide niobate LnNbO4 (LnNO) and tantalate LnTaO4 (LnTO) thin films (~ 100 nm) were prepared by sol-gel/spin-coating process on PZT/Al2O3 substrates and annealing at 1000 °C (Ln = Nd, Sm, Eu and Gd). The LnNO (NNO, SNO, ENO and GNO) and LnTO (NTO, STO, ETO and GTO) precursors of films were synthesized using Nb or Ta tartrate complexes. The different phase transformations were identified in LnNO or LnTO precursors from fluorite T′-structure via tetragonal T-LnNbO4 (NNO, SNO and GNO) or T-EuNb5O14 and T-NdTaO4, T-SmTa7O19, hexagonal H-EuTa7O19 and cubic C-GdTa7O19 to monoclinic M-LnNbO4 or M′-LnTaO4 during annealing at 700–1200 °C. The XRD results of LnNO or LnTO films confirmed the coexistence of monoclinic LnNbO4 or LnTaO4 phase in addition to the tetragonal as main phase at 1000 °C. In STO film, the single monoclinic M′-SmTaO4 phase was revealed. The surface morphology and topography of thin films were investigated by the SEM and AFM analysis. STO film was smoother with roughness of 3.23 nm in comparison with SNO (6.35 nm). Effect of lanthanides can contribute to the formation different polymorphs of these films for the application to environmental electrolytic thin film devices.

中文翻译：

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镧系元素对LnNbO 4 和LnTaO 4 薄膜相变和结构性能的影响

摘要 通过溶胶-凝胶/旋涂工艺在 PZT/Al2O3 衬底上制备了镧系元素铌酸盐 LnNbO4 (LnNO) 和钽酸盐 LnTaO4 (LnTO) 薄膜（~ 100 nm）并在 1000 °C 下退火（Ln = Nd, Sm, Eu和 Gd)。薄膜的 LnNO（NNO、SNO、ENO 和 GNO）和 LnTO（NTO、STO、ETO 和 GTO）前体是使用酒石酸铌或钽配合物合成的。通过四方 T-LnNbO4（NNO、SNO 和 GNO）或 T-EuNb5O14 和 T-NdTaO4、T-SmTa7O19、六方 H-EuTa7O19 和立方 C-，在来自萤石 T'-结构的 LnNO 或 LnTO 前体中发现了不同的相变GdTa7O19 在 700–1200 °C 退火期间转化为单斜晶 M-LnNbO4 或 M'-LnTaO4。LnNO 或 LnTO 薄膜的 XRD 结果证实了单斜 LnNbO4 或 LnTaO4 相除了作为主相的四方相在 1000°C 下共存。在STO影片中，显示出单个单斜 M'-SmTaO4 相。通过SEM和AFM分析研究了薄膜的表面形貌和形貌。与 SNO (6.35 nm) 相比，STO 膜更光滑，粗糙度为 3.23 nm。镧系元素的作用有助于形成这些薄膜的不同多晶型物，以应用于环境电解薄膜器件。