Y_(1-x)Pr_xBa_2Cu_3O_(7+δ)的红外反射谱  

INFRARED REFLECTION SPECTRA OF Y_(ι-x)Pr_xBa_2Cu_3O_(7+8)

作　　者：叶红娟[1] 冉中原 胡灿明[1] 田是映 刘竞青 黄叶肖[1] 赵忠贤[2] 

机构地区：[1]中国科学院红外物理国家重点实验室,上海200083 [2]中国科学院物理研究所,北京100080

出　　处：《物理学报》1992年第8期1345-1352,共8页Acta Physica Sinica

摘　　要：测量了温度范围为4.2—300K的Y_(1-x)Pr_xBa_2Cu_3O_(7+δ)(x=0,0.1,0.2,0.4,0.5,0.61.0)的红外反射谱,发现在低温下Ba模有双模行为,随着x值增大双模强度反转,在YBa_2Cu_3O_(7-δ)中已被判定为Y模的位于194cm^(-1)的反射峰的位置与Pr的含量无关,即用Pr部份或全部替代Y时此峰不发生频移。建议Pr在Y_(1-x)Pr_xBa_2Cu_3O_(7+δ),中是正4价,Pr的替代使原来可移动的空穴被定域在Pr的周围,使超导电性受到压制。The infrared refleotion spectra of Yl-xPrxBa2Cu3O7+8 (x = 0,0.1,0.2,0.4,0.5, 0.6, 1.0) are measured in the temprature range of 4.2 to 300K. The measurements show that Ba mode has double mode behavior, the strength of which inverses with increasing x, and that the position of the reflection peak at 194cm-1, which has been identified as Y mode of YBa2Cu3O7-8, is indenpendent of the density of Pr, i. e, the position of the peak does not change whether the Y is partially or totally substitued by Pr. This indicates that in Yl-xPrxBa2Cu3O7+8 the valence of Pr is tetra-valent. The substitution of Pr make the mobile holes localize around Pr, thereby lead to the suppression of superconductivity.

关 键 词：高TC 超导体 红外反射谱 元素替代 

分 类 号：O511.2[理学—低温物理]