화학공학소재연구정보센터
홈 로그인 로그아웃 연락처 사이트맵
HWAHAK KONGHAK, Vol.31, No.1, 9-15, February, 1993
Export Citation
CVD법에 의한 Y-Ba-Cu-O 고온초전도 박막의 제조와 열처리에 따른 특성변화
The Preparation of Y-Ba-Cu-O High-Tc Superconducting Thin Film by CVD and the Property Changes Induced by Heat Treatment
조익준, 신형식
초록
β-diketonate chelate 화합물을 원료물질로 하여 890℃에서 SrTiO3(100) 기판에 CVD법으로 Tc,onset= 91K(ΔTc=2K)인 Y-Ba-Cu-O 고온초전도 박막을 제조하였다. 그 박막을 아르곤 또는 산소분위기에서 열처리하였을 때, 산소의 확산이 박막의 전기적 특성값과 결정격자상수에 미치는 영향을 조사하였으며, 또 XPS를 이용하여 Y 3d, Ba 3d5/2, Cu 2p3/2 및 O 1s core-level의 광전자 방출로부터 산소확산에 의한 이들 각각의 core level line shape의 변화를 고찰하였다. 열처리조건에 따른 미세구조의 변화는 확인할 수 없었으나 Tc 변화는 현저하였으며, 재 산화 처리에도 처음의 Tc,zero값으로는 회복되지 않았다. 박막구성원소들의 XPS core-level spectrum은 박막의 질(quality), 표면오염 정도에 따라서도 변하고 있으나, 근본적으로 초전도상의 산소함량에 따라 크게 영향을 받는 것을 알 수 있었다.
The 91K(Tc, onset, △Tc=2K) Y-Ba-Cu-O thin films were prepared by CVD method on SrTiO3(100) substrates at 890℃ using β-diketonate chelate compounds of Y(thd)3, Ba(thd)2 and Cu(thd)2 as source mate-rials. The characteristic changes such as Tc, crystallinity, and XPS core spectra due to oxygen out-and in-dif-fusion induced by heat treatment were measured by use of AC-four prove technique, XRD and SEM. We have analyzed the spectral changes observed in the XPS core spectra of Y 3d, Ba 3d5/2, Cu 2p3/2 and Ols before and after heating Y-Ba-Cu-O films. The experimental results showed that Tc crystal structure, and core-level line shape of the elements in the probed surface region were influenced by the oxygen content, which varied by heating in Ar or O2 atmosphere. It is likely that the observed spectral changes are related to the oxygen deficency as well as to the film quality and extrinsic contamination of the surface.
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