La(Mg_(1/2)Sn_(1/2))O_(3)(LMS)ceramic was synthesized via the conventional solid-state reaction method.The main phase of the sample is LMS with a double perovskite structure(monoclinic P121/n1 symmetry),which is confi...La(Mg_(1/2)Sn_(1/2))O_(3)(LMS)ceramic was synthesized via the conventional solid-state reaction method.The main phase of the sample is LMS with a double perovskite structure(monoclinic P121/n1 symmetry),which is confirmed by X-ray diffraction.Scanning electron microscopy shows the sample is wellcrystallized with dense and uniform grains as well as clear grain boundaries.The Raman scattering and Fourier transform far-infrared reflection spectroscopies were employed to analyze the lattice vibrational modes of the sample.The Raman active modes were fitted by the Lorentz function,and the lattice vibrational modes were assigned and illustrated accurately.The four-parameter semiquantum model was applied to simulate the intrinsic dielectric properties,which agree well with the data calculated from the microscopic polarizability&damping angles.The A1g(La)Raman mode in A-site has a great impact on the dielectric loss,and F^(2)_(3u)mode makes the largest contribution to the dielectric constant and the dielectric loss.展开更多
基金the National Natural Science Foundation of China(Grant No.61501409)Natural Science Foundation of Shandong Province,China(Grant No.ZR2016EMM21)+1 种基金Scientific Research Foundation of Shandong University of Science and Technology for Recruited Talents(Grant No.2016RCJJ002)the Opening Project of State Key Laboratory of High Performance Ceramics and Superfine Microstructure(Grant No.SKL201503SIC).
文摘La(Mg_(1/2)Sn_(1/2))O_(3)(LMS)ceramic was synthesized via the conventional solid-state reaction method.The main phase of the sample is LMS with a double perovskite structure(monoclinic P121/n1 symmetry),which is confirmed by X-ray diffraction.Scanning electron microscopy shows the sample is wellcrystallized with dense and uniform grains as well as clear grain boundaries.The Raman scattering and Fourier transform far-infrared reflection spectroscopies were employed to analyze the lattice vibrational modes of the sample.The Raman active modes were fitted by the Lorentz function,and the lattice vibrational modes were assigned and illustrated accurately.The four-parameter semiquantum model was applied to simulate the intrinsic dielectric properties,which agree well with the data calculated from the microscopic polarizability&damping angles.The A1g(La)Raman mode in A-site has a great impact on the dielectric loss,and F^(2)_(3u)mode makes the largest contribution to the dielectric constant and the dielectric loss.
