Sati Aanchal, Pokhriyal Preeti, Kumar Anil, Anwar Shahid, Sagdeo Archna, Lalla N P, Sagdeo P R
Material Research Laboratory, Discipline of Physics, Indian Institute of Technology Indore, Indore-453552, India.
Synchrotron Utilization Section, Raja Ramanna Center for Advanced Technology, Indore 452013, India.
J Phys Condens Matter. 2021 Apr 20;33(16). doi: 10.1088/1361-648X/abf0bf.
The origin of ferroelectricity in the cubic phase of BaTiHfOhas been investigated. The presence of well-defined ferroelectric polarization versus electric field (PE) hysteresis loop in the samples with global cubic symmetry suggests the presence of 'local polar regions', induced possibly due to the huge difference in the electronegativity and also difference in the ionic radii of Hfand Tiions, which may lead to local structural disorder. The presence of polar regions is also supported through the appearance of A(TO) polar mode in Raman spectra which in principle should be absent in the samples with cubic symmetry. The results are discussed in terms of disorder-induced local dipoles due to the electronegativity difference between Hf and Ti ions.
对BaTiHfO立方相中铁电性的起源进行了研究。在具有整体立方对称性的样品中，明确的铁电极化与电场（P-E）滞后回线的存在表明存在“局部极性区域”，这可能是由于Hf和Ti离子的电负性差异巨大以及离子半径差异导致的，这可能会导致局部结构无序。拉曼光谱中A(TO)极性模式的出现也支持了极性区域的存在，原则上具有立方对称性的样品中不应出现这种模式。根据Hf和Ti离子之间的电负性差异导致的无序诱导局部偶极子对结果进行了讨论。
