Double Layer Processes of LBMO/YBCO and Crystalline Degradations
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0887-Q11-03.1
Double Layer Processes of LBMO/YBCO and Crystalline Degradations Hong Zhu1, Masanori Okada1, Hidetaka Nakashima1, Ajay K. Sarkar1, Hirofumi Yamasaki3, Kazuhiro Endo2, Tamio Endo1,2 1 Faculty of Engineering, Mie University, Tsu, Mie 514-8507, Japan 2 NeRI, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 3058568, Japan 3 ETRI, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 3058568, Japan Corresponding author: Tamio Endo, [email protected]
ABSTRACT
Double-layers of YBCO on LBMO and LBMO on YBCO were fabricated by ion beam sputtering technique. In the case of YBCO/LBMO, excellent a- and c-oriented overlying YBCO can be grown on underlying LBMO at 600- 650 °C. Crystallinity of the overlying YBCO is nearly the same with that of YBCO single-layers on MgO and LaAlO3 (LAO) substrates. Mosaicity of YBCO overlayer is much better than that of YBCO single-layers on MgO. It is noticed that the crystallinity of underlying LBMO can be improved, and the mosaicity is not degraded during the double-layer deposition. However, the inferiority is that surface roughness of the double-layer is much degraded. In the case of LBMO/YBCO, the excellent crystalline LBMO can be grown on the underlying a- and c-oriented YBCO at 650-700 °C. LBMO/a-YBCO clearly shows XRD peak separation but LBMO/c-YBCO does not show the peak separation. Time dependences of the crystalline degradations on YBCO/LBMO double-layers and corresponding single-layers are presented as well. The crystallinity of YBCO/MgO is easily degraded with time, but that of YBCO/LAO does not show the degradation. LBMO is stable if it is covered with YBCO overlayer.
INTRODUCTION
For nearly 20 years, high temperature superconductivity (HTS) in copper oxides and colossal magnetoresistance (CMR) in manganese oxides have drawn considerable attention to transition metal oxides with perovskite structures. Recently, CMR/HTS double-layer film, as one of the typical samples in so-called ferromagenet (Ferro)-supreconductor hybrids [1,2], has become an interesting topic in fundamental researches, such as vortex pinning and spin-polarized carrier injection, etc. In field of practical application, Ferro/HTC double-layer films have also been proposed as one of promising candidates for next generation of tunable microwave filter after realization of HTS microwave filter by the late 1990s [3-5]. In order to obtain the excellent double-layer films, knowledges on the correlation between the layers, such as underlayer quality dependence of overlayer and degradations of underlayer during overlayer deposition, are essentially important. In this paper, we report epitaxial growth
0887-Q11-03.2
of YBa2Cu3Ox (YBCO)/La(Ba)MnO3 (LBMO) and LBMO/YBCO double-layer films. The epitaxial qualities of double-layers are compared with that of the corresponding single-layers. The crystalline degradations of the underlayers after the overlayer deposition are also investigated.
EXPERIMENTAL DETAILS
The films were prepared by mean
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