四方相YBa_2Cu_3O_(7-δ)中E_u声子的异常反射带  

ANOMALOUS RESTSTRAHLENS OF Eu PHONONS IN TETRAGONAL YBa_2Cu_3O_(7_δ)

作　　者：张贵忠[1] 闫杰[2] 李增发[2] 张光寅[2] 

机构地区：[1]天津大学 [2]南开大学

出　　处：《天津大学学报》1991年第S1期44-47,共4页Journal of Tianjin University(Science and Technology)

摘　　要：报导人为改变氧含量的YBa_2Cu_3O_(7-δ)高温超导体声子剩余射线带系统反射光谱的研究结果。实验发现,在δ≈1.0的四方相结构中Eu声子的红外活性骤降;在由四方相向正交相转变过程中,声子活性显现出更强、更系统的降低。实验结果提供了声子参与超导过程的佐证,为进一步探索高温超导机理提供了一些线索。This paper presents the systematic investigations on the IR-activity of phonons in YBa_2Cu_3O_(7_δ) system whose oxygen contents were actively varied by quenching and vacuum annealing techniques. It was found that the IR-activity of all Eu phonons was profoundly decreased even in the nonsuperconducting tetragonal phase if the oxygen got a little more than 6. Together with the systematic decrease of phonon activity if the structure transferred from tetragonal into orthorhombic gradually, our results provided the strong evidence for the existence of the strong coupling between the phonons and the holes. The further reasonings were that the two-dimensional Cu-O networks may be responsible for the superconducting process and the strong coupling may exist in the form of polarons or bipolarons. Thus, a crucial clue to the further studies on the mechanism of high temperature superconductivity has been provided.

关 键 词：高温超导 声子剩余射线带 正交相 四方相 

分 类 号：N[自然科学总论]