Research on Development of Thermometers for Cryogenic Temperature in Magnetic fields

低温磁场温度计的研制研究

• 批准号: 02640244
• 负责人: YOSHIZAWA Masahito
• 金额: $ 1.02万
• 依托单位: Iwate 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 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02640244/
• 关键词: Thin film; Anderson localization; Thermometer; Low temperature; High magnetic field; Electrical resistivity; Acoustic properties; 電波物性

Zr-N sputtered films, which have been drawn attention as the best candidate for the thermometers at cryogenic temperature with magnetic fields, have been investigated by electrical and acoustical measurements. The results obtained in this research project are summarized as below.1. Classification of Zr-N films : Zr-N films fabricated with various sputtering conditions ; substrate temperature and nitrogen partial pressure, can be classified and divided into two groups by the resistance ratio. between room and helium temperatures.2. Origin of small magnetoresistance : Magnetoresistance(MR)of Zr-N films is investigated by the measurements in the field up to 30T. It is found that MR of Zr-N consists of various contributions from quantum interference, spin-orbit and interaction effects. The small MR in weak field arises from accidental cancellation of these contributions. The possibility of occurrence of ferromagnetism was also suggested.3. Universal behavior in temperature dependence of electrical conductivity : We present attempts for finding the universal function which describes T dependence of conductivity. The conductivity sigma is described as sigma=sigma_0+AAOT for major parts of samples at high temperatures, and as sigma=sigma_0+A(T-T_0)^<gamma> at low temperatures. The relations among gamma, A, etc. are found.4. Discovery of novel elastic anomalies : The velocity of surface acoustic wave shows remarkable anomalies as a function of temperature. The strongly localized sample with high resistance ratio shows a broad minimum at above 300 K and a softening toward low temperature. The weakly localized sample shows sole a broad minimum at 15 K. These elastic anomalies and the relation to the localization are discussed based on two-level-system.From the series of investigations, the physical properties of Zr-N films has been made clear. These results would lead the successful development of then-nometers for the use at cryogenic temperature in magnetic field.

Zr-N溅射薄膜作为低温磁场温度计的最佳候选而受到关注，已通过电学和声学测量进行了研究。本研究项目取得的主要成果如下： 1． Zr-N薄膜的分类：各种溅射条件下制备的Zr-N薄膜；基材温度和氮分压，可以按电阻比分为两组。室温和氦气温度之间。2。小磁阻的起源：通过在高达30T的磁场中测量来研究Zr-N薄膜的磁阻（MR）。研究发现Zr-N的MR由量子干涉、自旋轨道和相互作用效应的多种贡献组成。弱场中的小 MR 是由于这些贡献的意外抵消而产生的。并提出了铁磁性发生的可能性。 3．电导率温度依赖性的通用行为：我们尝试寻找描述电导率 T 依赖性的通用函数。高温下样品主要部分的电导率 sigma 描述为 sigma=sigma_0+AAOT，低温下样品的电导率 sigma 描述为 sigma=sigma_0+A(T-T_0)^<gamma>。找出了gamma、A等之间的关系； 4．新型弹性异常现象的发现：声表面波的速度随温度变化而表现出显着的异常现象。具有高电阻比的强局部化样品在 300 K 以上显示出较宽的最小值，并向低温软化。弱局域化的样品仅在 15 K 处显示出较宽的最小值。基于两能级系统讨论了这些弹性异常及其与局域化的关系。通过一系列的研究，Zr-N 薄膜的物理性质已经明确。 。这些结果将导致用于低温磁场的纳米计的成功开发。

项目成果

Fgf10 is essential for limb and lung formation

• DOI: 10.1038/5096
• 发表时间: 1999-09-13
• 期刊: Nature Genetics
• 影响因子: 30.8
• 作者: K. Sekine;H. Ohuchi;Masanori Fujiwara;M. Yamasaki;T. Yoshizawa;Takashi Sato;N. Yagishita;Daisuke Mat
• 通讯作者: Daisuke Mat