Perejón Antonio, Gil-González Eva, Sánchez-Jiménez Pedro E, Criado José M, Pérez-Maqueda Luis A
Instituto de Ciencia de Materiales de Sevilla, Consejo Superior de Investigaciones Científicas-Universidad de Sevilla . Calle Américo Vespucio 49, Sevilla 41092, Spain.
Departamento de Química Inorgánica, Facultad de Química, Universidad de Sevilla , Sevilla 41071, Spain.
Inorg Chem. 2015 Oct 19;54(20):9876-84. doi: 10.1021/acs.inorgchem.5b01654. Epub 2015 Oct 2.
Ceramics of Bi(1-x)Y(x)FeO3 solid solutions (x = 0.02, 0.07, and 0.10) have been prepared by mechanical activation followed by sintering. The effect of yttrium content on the structural, electrical, and optical properties of the materials has been studied. Thus, single-phase solid solutions with rhombohedral R3c structure have been achieved for x = 0.02 and 0.07, while for x = 0.10 the main R3c phase has been detected together with a small amount of the orthorhombic Pbnm phase. Multiferroic properties of the samples, studied by differential scanning calorimetry (DSC), showed that both T(N) and T(C) (temperatures of the antiferromagnetic-paramagnetic and ferroelectric-paraelectric transitions, respectively) decrease with increasing yttrium content. The nature of the ferroelectric-paraelectric transition has been studied by temperature-dependent X-ray diffraction (XRD), which revealed rhombohedral R3c to orthorhombic Pbnm phase transitions for x = 0.07 and 0.10. On the other hand, for x = 0.02 the high-temperature phase was indexed as Pnma. Optical properties of the samples, as studied by diffuse reflectance spectroscopy, showed low optical band gap that decreases with increasing yttrium content. Prepared ceramics were highly insulating at room temperature and electrically homogeneous, as assayed by impedance spectroscopy, and the conductivity increased with x.
通过机械活化后烧结制备了Bi(1 - x)Y(x)FeO3固溶体陶瓷（x = 0.02、0.07和0.10）。研究了钇含量对材料结构、电学和光学性能的影响。因此，对于x = 0.02和0.07，获得了具有菱方R3c结构的单相固溶体，而对于x = 0.10，检测到主要的R3c相以及少量的正交Pbnm相。通过差示扫描量热法（DSC）研究的样品的多铁性性质表明，T(N)和T(C)（分别为反铁磁 - 顺磁和铁电 - 顺电转变温度）均随钇含量的增加而降低。通过变温X射线衍射（XRD）研究了铁电 - 顺电转变的性质，结果表明对于x = 0.07和0.10，存在从菱方R3c到正交Pbnm的相变。另一方面，对于x = 0.02，高温相被标定为Pnma。通过漫反射光谱研究的样品的光学性质表明，光学带隙较低，且随钇含量的增加而降低。通过阻抗谱分析，制备的陶瓷在室温下具有高绝缘性且电均匀性良好，并且电导率随x增加。
