The crystal structures and piezoelectric properties of gallium-substituted BiFeO₃ (BiFe_1–xGa_xO₃) thin films on (110) LaAlO₃ substrates were investigated. The structure of BiFe_1–xGa_xO₃ thin films was found to change from rhombohedral (x = 0) to a (101)-oriented monoclinic phase with a giant c/a ratio (x = 0.40) through two phase coexistence compositions (x = 0.10, 0.20) as the Ga content was increased. The piezoelectric response of the (101)-oriented monoclinic BiFe_1–xGa_xO₃ thin film with x = 0.40 was 1.6 times that of a corresponding (001)-oriented one. Such behavior is unique to the monoclinic phase where polarization can rotate and can be attributed to the fact that the a- and b-axes are more sensitive to polarization rotation than the c-axis.

中文翻译：

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具有极化旋转的取向控制的 BiFe1-xGaxO3 薄膜中增强的压电响应

研究了(110) LaAlO ₃衬底上镓取代的BiFeO ₃ (BiFe _{1– x} Ga _x O ₃ )薄膜的晶体结构和压电性能。发现 BiFe _{1– x} Ga _x O ₃薄膜的结构通过两相共存组成从菱面体 ( x = 0) 变为具有巨大c / a比 ( x = 0.40)的 (101) 取向单斜相( x = 0.10, 0.20) 随着 Ga 含量的增加。(101) 取向的单斜 BiFe 的压电响应x = 0.40 的_{1– x} Ga _x O ₃薄膜是相应的 (001) 取向薄膜的1.6 倍。这种行为是唯一的单斜晶相，其中极化可旋转并可以归因于一个事实，即A-和b -axes是比偏振旋转更敏感Ç轴。