Laboratoire des Matériaux et du Génie Physique, CNRS UMR 5628, Grenoble Institute of Technology, Minatec, 3, parvis Louis Néel, 38016 Grenoble, France.
J Phys Condens Matter. 2010 Apr 28;22(16):165901. doi: 10.1088/0953-8984/22/16/165901. Epub 2010 Apr 6.
We report a temperature-dependent Raman scattering investigation of DyScO(3) and GdScO(3) single crystals from room temperature up to 1200 °C. With increasing temperature, all modes decrease monotonically in wavenumber without anomaly, which attests to the absence of a structural phase transition. The high temperature spectral signature and extrapolation of band positions to higher temperatures suggest a decreasing orthorhombic distortion towards the ideal cubic structure. Our study indicates that this orthorhombic-to-cubic phase transition is close to or higher than the melting point of both rare-earth scandates ([Formula: see text]), which might exclude the possibility of the experimental observation of such a phase transition before melting. The temperature-dependent shift of Raman phonons is also discussed in the context of thermal expansion.
我们报告了 DyScO(3) 和 GdScO(3) 单晶从室温到 1200°C 的温度依赖拉曼散射研究。随着温度的升高，所有模式的波数都单调下降，没有异常，这证明没有结构相变。高温光谱特征和带位置的外推到更高的温度表明，正交畸变朝着理想的立方结构逐渐减小。我们的研究表明，这种正交相到立方相的转变接近于或高于两种稀土钇酸盐的熔点([Formula: see text])，这可能排除了在熔融之前实验观察到这种相变的可能性。还讨论了拉曼声子的温度依赖性位移与热膨胀的关系。
