VACANCY-INDUCED AND 2-PHONON RAMAN-SCATTERING IN ZRCX, NBCX, HFCX, AND TACX
VACANCY-INDUCED AND 2-PHONON RAMAN-SCATTERING IN ZRCX, NBCX, HFCX, AND TACX
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DOI：
10.1002/pssb.2221080225
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发表时间：
1981-01-01
影响因子：
1.6
通讯作者：
WILLIAMS, WS
中科院分区：
文献类型：
--
作者：
WIPF, H;KLEIN, MV;WILLIAMS, WS
研究了亚化学计量过渡金属碳化物的拉曼散射。这些立方固体中的碳空位诱导了一个基本上反映声子态密度的单声子谱。超导Vb族碳化物NbC 0. 98和TaC 0. 99具有显示特征声子软化的单声子拉曼光谱。还观察到强的A + A和O + A双声子峰。在具有低Tc的NbC0.76中，单声子峰变硬，双声子强度减弱。NbC0.98和TaC0.99的机械抛光减少了双声子散射，并硬化和加宽了单声子谱。非超导相邻的IVb族碳化物ZrC0.96、ZrC0.87和HfC0.99具有较高频率的单声子峰，而没有双声子特征。
Raman scattering is studied in the substoichiometric transition metal carbides. The carbon vacancies in these cubic solids induce a one‐phonon spectrum that essentially mirrors the phonon density of states. The superconducting group Vb carbides NbC0.98and TaC0.99have one‐phonon Raman spectra that show characteristic phonon softening. Strong A + A and O + A two‐phonon peaks are also seen. In NbC0.76, which has a low Tc, the one‐phonon peaks harden, and the two‐phonon intensities weaken. Mechanical polishing of NbC0.98and TaC0.99reduces two‐phonon scattering and hardens and broadens the one‐phonon spectra. The non‐superconducting adjacent group IVb carbides ZrC0.96, ZrC0.87, and HfC0.99have higher‐frequency one‐phonon peaks and no two‐phonon features.