Raman and infrared spectroscopic investigations on the crystal structure and phonon modes of LaYbO3 ceramics
Raman and infrared spectroscopic investigations on the crystal structure and phonon modes of LaYbO3 ceramics
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DOI：
10.1088/0953-8984/17/17/027
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发表时间：
2005-05
期刊：
影响因子：
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通讯作者：
R. L. Moreira;A. Feteira;A. Dias
中科院分区：
文献类型：
--
作者：
R. L. Moreira;A. Feteira;A. Dias
LaYbO3是一种具有正交结构的高度畸变的钙钛矿。然而，它的确切空间群一直是一个有争议的问题。极性Pna 21和中心对称Pnma空间群（Z = 4）都被提出来描述其室温结构。在这项工作中，我们提出的光学光谱研究拉曼散射和红外反射率的LaYbO 3陶瓷在1600 °C烧结。结果使我们能够提出一个新的中心对称Cmcm空间群的这种化合物，并显示声子的主要贡献，其介电常数和品质因数在微波频率。
LaYbO3 is a highly distorted perovskite with orthorhombic structure. However, its exact space group has been a matter of debate. Both the polar Pna 21 and the centrosymmetric Pnma space groups, with Z = 4, have been proposed to describe its structure at room temperature. In this work we present optical spectroscopic investigations by Raman scattering and infrared reflectivity of LaYbO3 ceramics sintered at 1600 °C. The results allowed us to propose a new centrosymmetric Cmcm space group for this compound, and to show which phonons give the main contributions to its dielectric constant and quality factor at microwave frequencies.