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.

我尝试用离子束辅助离子束溅射的方法，在较低的生长温度下制备高T_c超导薄膜。为了达到这一目的，我研制了一种离子束辅助离子束溅射薄膜加工设备。在真空室中设置有溅射离子枪、辅助离子枪、靶架和基片架。在衬底附近设置一个氧气喷嘴。制备了BiSrCaCuO系薄膜，研究了衬底温度(Ts)和氧气压(P)对薄膜性能的影响。对于P=1×10~(-4)&gt~(-4)，在ts=600~700ﾟC下制备的薄膜中，Bi和Cu的含量很低，并且在RT时是绝缘的。对于P=3x10^&lt；-4；Torr，薄膜是导电的，其电阻率为1-100 omega cm。对于P=3x10^&lt；-4&gt；Torr，在薄膜生长过程中，当O+辅助离子辐照时，薄膜的电阻率为几个欧米伽厘米，X射线衍射峰为2201相。然而，它们的组成约为2212。离子助剂具有表面迁移和强氧化作用，抑制了铋的蒸发，有利于晶体结构的形成。该助剂制备的薄膜在80 0ﾟC下热处理时，出现2 2 0 1和2 2 12相的X射线衍射峰，并出现超导转变。当ts=700ﾟC时，薄膜的起始温度为91K。没有助剂的薄膜没有观察到同样的退火效果。从而阐明了离子助剂对晶体生长的潜在作用。