Structural Changes in Molten Vb and VIb Metals and Ultra-Sound Propagation.

熔融 Vb 和 VIb 金属的结构变化以及超声波传播。

基本信息

批准号：
10650648
负责人：
TSUCHIYA Yoshimi
金额：
$ 2.3万
依托单位：
NIIGATA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10650648/
关键词：
SOUND VELOCITY LIQUID As STRUCTURAL CHANGE TERMODYNAMICS TWO-LIQUID PHASE STABILITY PEIERLS DISTORTION struetural change thermodynamics molton metal As-Te

项目摘要

We have renewed a gated RF amplifier with the grant and set up a stable ultra-sonic measurement gear, with which we have measured systematically the velocity of sound in various molten alloys at high temperatures. To compliment the ultra-sound measurements, we have measured the density with the gamma-ray attenuation method. Further we have derived the new thermodynamic relations which enable to elucidate the concentration fluctuations induced by local structural changes. During the period of the grand, we have published ten papers in well-established international journals. To proceed the research project, I was reviewed by Dr. C. Bergman at CNRS, Marseille and Dr. F. Sommer at MPI, Stuttgart in 1998.Main results are1. Structural changes in the As-Te system : the phase diagram has been investigated by detecting a minimum in the sound velocity and/or the thermal expansion coefficient as a function of temperature. The minimum has been confirmed up to 60 at.% of As. The transition point i … More n the structural change in the super-cooled molten As has been determined to be 734 ± 6℃ by an extrapolation.2. Structural changes in the molten II b-VI b system : by measuring the sound velocity, it has been shown that the molten CdTe has very stable structure whereas the molten HgTe undergoes continuous structural changes around the melting point. The transition point in the molten HgTe has been determined.3. The thermodynamic relations connecting structural changes and concentration fluctuations in a binary mixture : the new thermodynamic relations which enable to elucidate the concentration fluctuations induced by local structural changes have been derived. Application has been made to show the origin of the looped two-melt phase in the molted S-Te system.The concentration fluctuations induced by structural changes are one of the key points to be clarified to grow high quality crystals of the compound semiconductors. We are planning to investigate systematically the phenomenon by measuring the specific heat as well as the sound velocity and density of molten compound semiconductors at high temperatures. Less

我们已经使用赠款续签了一个封闭式的RF放大器，并建立了稳定的超音量测量齿轮，在高温下，我们已经系统地测量了各种熔融合金中声音的速度。为了补充超声测量，我们已经用伽马射线衰减方法测量了密度。此外，我们得出了新的热力学关系，该关系可以阐明局部结构变化引起的浓度波动。在盛大的时期，我们在公认的国际期刊上发表了十篇论文。为了继续研究项目，CNRS，Marseille和MPI的F. Sommer博士在1998年在MPI的F. Sommer博士进行了审查。 AS-TE系统的结构变化：通过检测声速和/或热膨胀系数的最小值来研究相图。最低限度已确认为60个As的。％。过渡点i…更n，超冷熔融的结构变化被推断为734±6℃2。熔融II B-VI B系统的结构变化：通过测量声速，已经表明熔融CDTE具有非常稳定的结构，而熔融HGTE在熔点周围经历了连续的结构变化。已经确定了熔融HGTE中的过渡点3。在二进制混合物中连接结构变化和浓度波动的热力学关系：已得出了可以阐明局部结构变化引起的浓度波动的新热力学关系。已经应用了在摩尔的S-TE系统中显示循环两键相的起源。结构变化引起的浓度波动是要阐明的关键点之一，以增强复合半导体的高质量晶体。我们计划通过测量高温下的特定热量以及熔融化合物半导体的声速和密度来系统地研究现象。较少的