Improvement of superconducting properties by inducing stress

Abstract

Strained lattice Xe-doped YBa(x)Cu(y)O(z) thin films were deposited on unheated (100) Si substrates using the single-target Xe ion-beam sputtering technique. The films were annealed in flowing oxygen at 100-500 C for 24 h. Their resistances could be dropped by about five orders of magnitude in the transition width of 50-100 K. The annealed films had a YBa2Cu3O(6.8) phase with compressed a-b lattice planes and an unstrained lattice YBa2Cu3O6 phase. Because xenon reacted with oxygen during annealing, the binding energy of the Xe 3d signal was lowered by 3 eV compared with sole xenon, and O 1s signals had a binding energy with the centroid at 530.1 eV. Lattice compression and a transition temperature to very low resistivity were dependent of the intensity of the 530.1 eV O 1s signals.

単一標的Xeイオンビームスパッタリング法を用いて、非加熱(100)Si基板上に、Xeをドープした格子の歪んだYBa(x)Cu(y)O(z)薄膜を蒸着した。この膜を酸素流中において100-500度Cで24時間アニールした。転移幅50-100度Kにおいて抵抗は約5桁減少した。アニールした膜は、圧縮したa-b面をもつYBa(2)Cu(3)O(6.8)相と、格子歪みのないYBa2Cu3O6相からなっていた。アニーリングの間にXeは酸素と反応したので、Xe 3d信号の結合エネルギーはXe単独の場合に比較して3eV低下し、O 1s信号の結合エネルギーは530.1eVに中心を持っていた。格子の圧縮と低抵抗状態への転移温度は530.1eVのO 1s信号の強度に依存した。