Inelastic neutron scattering measurements on the transverse acoustic and lowest optic modes in doped with lithium
Inelastic neutron scattering measurements on the transverse acoustic and lowest optic modes in doped with lithium
复制标题
锂掺杂横向声波和最低光学模式的非弹性中子散射测量
DOI：
10.1088/0953-8984/8/9/004
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
B. Hennion
中科院分区：
文献类型：
--
作者：
R. Klein;G. Kugel;B. Hennion
通过非弹性中子散射研究了 1% 和 5% Li 的两种晶体。从室温到 10 K，在 [100] 方向上测量了横向声模和最低光学模。表示了模软化、阻尼和强度的波矢量依赖性。假设氧离子具有各向异性非线性极化率，则在扩展壳模型的框架内分析测量的色散。在此模型的基础上，计算结构因子并与测量的声子强度进行比较。讨论了锂取代对极化率非线性特性影响的结论。
Two crystals of with 1% and 5% Li have been investigated by inelastic neutron scattering. The transverse acoustic and lowest optic modes have been measured in the [100] direction from room temperature down to 10 K. The wavevector dependences of the mode softening, damping and intensities are represented. The measured dispersions are analysed in the framework of an extended shell model assuming an anisotropic non-linear polarizability of the oxygen ion. On the basis of this model, structure factors are calculated and compared with measured phonon intensities. Conclusions on the influence of the lithium substitution on the non-linear character of the polarizability are discussed.