【摘要】 运用紧束缚双带模型对MX化合物晶格振动的计算发现 ,晶格振动谱由一条声频支和三条光频支组成 ,进一步得到了出现元激发时 ,晶格振动色散关系中的分立频率和相应的定域振动模 .在MX化合物红外吸收谱的计算中发现对应不同元激发红外谱具有不同的特征 .更多还原

【Abstract】 In our calculations of lattice vibration, one acoustic and three optical branches were found to compose the phonon vibrating spectrum. Some isolated modes with frequencies lying outside the continuum branches arise under the defect states. These localized modes result in the sharp peaks in the infrared absorption and Raman spectra.更多还原