作　　者： ; ; ;

机构地区： 聊城大学

出　　处： 《聊城大学学报（自然科学版）》 2004年第3期21-22,26,共3页

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： 非单调 铁磁系统 薄膜 自旋 单层膜 磁性 超导转变温度 高温超导材料

领　　域： [电气工程] [一般工业技术] [理学] [理学]