Raman Spectra of NH4-TCNQ-I and -II
Raman Spectra of NH4-TCNQ-I and -II
复制标题
NH4-TCNQ-I 和-II 的拉曼光谱
DOI：
10.1143/jpsj.55.1177
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发表时间：
1986
影响因子：
1.7
通讯作者：
A. Mitsuishi
中科院分区：
文献类型：
--
作者：
M. Yoshikawa;S. Nakashima;A. Wada;A. Mitsuishi
观测到了NH4-TCNQ-I和NH4-TCNQ-II在相变温度TC=301 K和215K范围内的偏振拉曼光谱。低频模的强度随相变温度的升高而迅速减小。对两种晶体在低温阶段的低频模式进行了指认。比较了NH4-TCNQ-I和碱金属-TCNQ盐的拉曼光谱，发现NH4-TCNQ-I与K-TCNQ分子在链上的堆积排列相似。讨论了TCNQ分子的二聚化引起的拉曼选择规则和拉曼极化率的变化对光强的影响。
Polarized Raman spectra of NH 4 -TCNQ-I and -II have been observed in the temperature range including phase transition temperatures T c =301 and 215 K, respectively. The intensity of low frequency modes decreases rapidly with approaching the phase transition temperature from below. Mode assignment has been made on low frequency modes in the low temperature phase of two crystals. A comparison among Raman spectra of NH 4 -TCNQ-I and alkali metal-TCNQ salts reveals that NH 4 -TCNQ-I resembles K-TCNQ in the stacking arrangement of the TCNQ molecules in the chains. The intensity variation is discussed in terms of the change of Raman selection rule and Raman polarizability by the dimerization of the TCNQ molecules.