钙钛矿La_(2/3)Ca_(1/3)MnO_3/YBa_2Cu_4O_8/La_(2/3)Ca_(1/3)MnO_3三层薄膜的磁输运性能  

Magnetictransport Properties of Perovskite La_(2/3)Ca_(1/3)MnO_3/YBa_2Cu_4O_8/ La_(2/3)Ca_(1/3)MnO_3Trilayer Films

作　　者：张丽[1] 梁宝龙[2] 赵昆[2] 

机构地区：[1]聊城大学资产与实验管理处,山东聊城252059 [2]物理科学与信息工程学院

出　　处：《聊城大学学报（自然科学版）》2004年第3期21-22,26,共3页Journal of Liaocheng University:Natural Science Edition

摘　　要：高温超导材料YBa2Cu4O8(YBCO)和铁磁材料La2/3Ca1／3MnO3(LCMO)形成的三层薄膜LCMO／YBCO／LCMO由对靶溅射技术制得.与YBCO单层薄膜相比,由于超导／铁磁系统中的磁性邻近效应,三层薄膜表现出较低的超导转变温度(TC,ON).与LCMO单层膜相比,三层薄膜的金属半导体转变温度(TMS)被提高并且强烈依赖于YBCO层的厚度.随中间层厚度的变化,磁电阻显示出非单调行为,长振荡周期被发现.结果表明,当YBCO处于正常态时两层LCMO膜之间存在着磁性自旋相互作用.Trilayer films in which a superconducting YBa2Cu4O8 (YBCO) layer is sandwiched between two ferromagnetic La2/3Ca1/3MnO3 (LCMO) layers are formed by facing-target sputtering technique. The difference of superconducting transition temperature (TC,ON) between YBCO single layer and LCMO/YBCO/LCMO trilayers as functions of YBCO thickness is described by the magnetic proximity effect in superconductor/ferromagnet structure. In contrast to that for LCMO films,the metal-semiconductor transition temperature (TMS) for LCMO/YBCO/LCMO films is enhanced and strongly depends on the YBCO layer thickness. The magnetoresistance (MR) ratio shows a non-monotonic behavior and a long oscillatory period is found. These results imply that the magnetic spin interaction between the two LCMO layers may exist through the normal-conductive YBCO layer.

关 键 词：LA2/3CA1/3MNO3 非单调 铁磁系统 薄膜 自旋 单层膜 磁性 YBCO 超导转变温度 高温超导材料 

分 类 号：TM26[一般工业技术—材料科学与工程] O482[电气工程—电工理论与新技术]