【摘要】 在群论分析的基础上,研究了620～640cm^-1红外光谱峰的峰型、峰频、峰半宽度及强度随淬火温度的变化规律.证实了在YBa₂Cu₃O_7-δ处于正交相时,该峰本质上是α轴Cu-O-Cu局域模B_3u和一维Cu-O准局域模B_2u迭加而成,处于四方相时,两模简并成一个模.并讨论了YBa₂Cu₃O_7-δ中载流子对入射红外辐射的屏蔽效应.更多还原

【Abstract】 On the basis of group theory analysis, the variation of the shape, frequency shift, linewidth and intensity of 620～640cm^-1 IR absorption peak （P1） in YB_a2Cu₃O7_7-6system vs quenching temperature has been systematically studied. It is verified that this peak consists of two overlapped peaks as YBa₂Cu₃O₇-δ is of orthorhombic phase at δ<0.5; onc located at high frequency is coorresponding to the localized mode B_?u of Cu-O-Cu vibration centre between Ba layers on a axis, and the other one at low frequency is corresponding to the quasi-localized vibration mode B_2u of Cu-O bond induced by the oxygen-vacancy in one dimensional Cu-O chain on b axis. These two modes are identical to each other in the tetragonal phase. Meanwhile, it has been also found at orthorhombic-to-tetragonal （O-T） transition that the intensity of the p₁ peak, which should begin to reduce, still increases. This anomalous phonomenon is attributed to the weakening of the effect of carrier screening on infrared radiation.更多还原