CRYSTAL DYNAMICS OF LEAD TELLURIDE
CRYSTAL DYNAMICS OF LEAD TELLURIDE
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DOI：
10.1098/rspa.1966.0182
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发表时间：
1966-01-01
影响因子：
--
通讯作者：
ELCOMBE, MM
中科院分区：
文献类型：
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作者：
COCHRAN, W;COWLEY, RA;ELCOMBE, MM
用非弹性中子散射技术测定了碲化铅在某些对称方向上传播的简正振动频率。结果被用来推导刚性离子模型和壳层模型的原子间作用力参数。后一种模型考虑了离子的极化率。这两种模型都不是很成功，但最好的壳体模型确实提供了与结果很好的拟合，并已用于计算频率分布和比热。热膨胀和横向光学模寿命的计算表明，碲化铅中的非简谐相互作用比简单的碱卤化物中的非简谐相互作用复杂得多。详细讨论了掺杂对晶格振动的影响，结果表明，较大的影响仅限于色散曲线的长波区。详细计算了光学支路的色散随掺杂浓度的变化。简要讨论了这些效应对各种实验研究的重要性。
The frequencies of the normal modes of vibration of lead telluride propagating in certain symmetric directions have been determined by inelastic neutron scattering techniques. The results have been used to deduce the parameters of rigid ion models and of shell models for the interatomic forces. The latter models take account of the polarizability of the ions. Neither type of model is very successful, but the best shell model does provide a good fit to the results and has been used to calculate the frequency distribution and specific heat. Calculations of the thermal expansion, and of the lifetime of the transverse optic modes, show that anharmonic interactions in lead telluride are considerably more complex than in the simple alkali halides. A detailed account of the effect of doping on the lattice vibrations is given, in which it is shown that large effects are limited to the long wavelength regions of the dispersion curves. Detailed calculations are presented for the dispersion of the optical branches as a function of the dopant concentration. The importance of these effects for different kinds of experimental studies is briefly discussed.