Low Temperature Film Growth of Epitaxial Bi High-Tc Superconducting Single Crystals by Ion Beam Assisted Ion Beam Sputtering

离子束辅助离子束溅射外延Bi高温超导单晶的低温成膜

• 批准号: 02805035
• 负责人: ENDO Tamio
• 金额: $ 1.28万
• 依托单位: Mie University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02805035/
• 关键词: Preparation of high Tc superconducting thin films; 2212 phase of Bi system; Ion beam assist equipment; Ion beam sputtering equipment; Surface migration; Promotion of oxidation; Annealing; Transition temperature of 91 K; イオンビームアシスト; イオンビームスパッタ; B

I tried to prepare Bi high Tc superconducting thin films at low growth temperature by an ion beam assited ion beam sputtering. To attain this purpose, I made an equipment of thin film processing by the ion beam assisted ion beam sputtering. There arranged a sputter ion gun, an assist ion gun, a target holder and a substrate holder in a vacuum chamber. A nozzle of oxigen gas was set near the substrate. The films of BiSrCaCuO system were prepared, and dependences of film properties on the substrate temperature (Ts) and the oxygen patial pressure (P) were investigated. For P=1X10^<-4> Torr, Bi and Cu are poor in the films prepared at Ts=600-700 ﾟC and they are insulating at rt. For P=3X10^<-4> Torr, the films are conducting and have resistivity of 1-100 OMEGA cm. For P=3X10^<-4> Torr, when O+ assist ions are irradiated during the film growth, the films have the resistivity of several OMEGA cm and show XRD peaks of2201 phase. However, their composition is about 2212. The ion assisting has effects of a surface migration and a strong oxidation which suppres evaporation of Bi and facilitate to form crystal structure. When the films prepared by the assisting are annealed at 800 ﾟC , they show XRD peaks of 2201 and 2212 phases and show superconducting transition. The onset temperature is 91 K for the film for Ts=700 ﾟC . The same annealing effect is not observed for the films without the assisting. Therefore, the potential effect of the ion assisting on crystal growth is clarified.

本文尝试用离子束辅助离子束溅射法在低温下制备Bi系高温超导薄膜。为了达到这一目的，我制作了一台离子束辅助离子束溅射薄膜加工设备。在真空室中设置溅射离子枪、辅助离子枪、靶保持器和基板保持器。在衬底附近设置氧气喷嘴。制备了BiSrCaCuO系薄膜，研究了衬底温度（Ts）和氧分压（P）对薄膜性能的影响。当P= 1 × 10 ~（13）Torr时<-4>，在Ts=600-700 ℃下制备的薄膜中Bi和Cu含量较少，室温下为绝缘态，当P= 3 × 10 ~（13）Torr时<-4>，薄膜为导电态，电阻率为1-100 Ω cm。当P= 3 × 10 ~（-4）Torr时<-4>，在薄膜生长过程中引入O ~+辅助离子，薄膜电阻率可达几Ω cm，XRD谱峰为2201相。然而，它们的组成约为2212。离子辅助具有表面迁移和强氧化的效果，其抑制Bi的蒸发并促进形成晶体结构。辅助法制备的薄膜经800 ℃退火后，出现2201和2212相的XRD峰，表现出超导转变。当Ts=700 ℃时，薄膜的起始温度为91 K。对于没有辅助的薄膜，没有观察到相同的退火效果。从而阐明了离子辅助对晶体生长的潜在影响。