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.

我尝试通过离子束辅助离子束溅射在低生长温度下制备Bi高Tc超导薄膜。为了实现这一目的，我制作了一种通过离子束辅助离子束溅射进行薄膜加工的设备。真空室中设置有氧气喷嘴、辅助离子枪、靶材支架和衬底支架，制备BiSrCaCuO体系的薄膜。并研究了薄膜性能对衬底温度(Ts)和氧气压(P)的依赖性，对于P=1X10^<-4>Torr，在Ts=600-700℃下制备的薄膜中Bi和Cu较差。 C并且它们在室温下是绝缘的。对于P＝3X10 ^ -4 Torr，膜是导电的并且具有1-100Ωcm的电阻率。 P＝3X10^-4Torr，在薄膜生长过程中照射O+辅助离子时，薄膜具有数Ωcm的电阻率，并显示出2201相的XRD峰，但其组成约为2212。离子辅助有影响。当辅助制备的薄膜在50℃退火时，会发生表面迁移和强氧化，从而抑制Bi的蒸发并有利于形成晶体结构。在 800 ℃ 时，它们显示出 2201 和 2212 相的 XRD 峰，并且对于 Ts=700 ℃ 的薄膜，显示出超导转变的起始温度。阐明了离子对晶体生长的潜在影响。