【摘要】 本文对钾青铜低温喇曼光谱进行了研究,观察到由77K到180K升温时具有部分软化特征的电荷密度波振幅模和两个与相变相联系的新附加声子线。利用平均场理论对软模进行分析,给出了电荷密度波的Peierls能隙2△（0）、电声子耦合常数λ及电荷密度波的有效质量m*_CDW的估计值分别为0.13eV、0.26及337m_e。这些参数与其他作者通过中子散射、红外及自旋磁化率等实验得到的结果相符,对深入理解电荷密度波动力学本质有重要意义。同时,对振幅模部分软化的原因及强度在100K附近的异常现象也进行了分析讨论。更多还原

【Abstract】 Temperature dependence of the Raman spectra of potassium blue bronze K0.3MoO3 as measured. The amplitude mode of charge-density-wave (CDW) which was partially softened towards Peierls transition temperature and two strong new modes at about 76cm-1 and 86 cm-1 in the distored CDW state were observed. The energy of the soft mode in the measured temperature range were qualitatively elucidated by the mean-field theory. Three parameters: Peierls gap 2△(0), the ratro of the CDW effective mass to electron mass mCDW/me and electron-phonon coupling constant λ are estimated to 0.13eV, 337 and 0.26, respectively, which are in agreement with the results by neutron scattering, infrared spectra and spin susceptibility measurements. The origin of the partial softening of the amplitude mode and the anomalous behavior of the intensity near 100K were also discussed.更多还原