"Neutron Scattering Study on Photosensitive Magnetic Clusters in Semimagnetic Semiconductors"

《半磁半导体中光敏磁团簇的中子散射研究》

基本信息

批准号：
07455417
负责人：
KAJITANI Tsuyoshi
金额：
$ 1.02万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1997
项目状态：
已结题

项目摘要

Present study was aimed to obtain structural characteristics of optically sennsitive magnetic clusters and its related physical properties of magnetic clusters in the II-VI-type semiconductors deped with magnetic metal atoms. Single crystals of Zn_<1-x>Mn_xTe with x=0.3-0.6 were prepared by the standard Bridgeman method. Structural study on the average lattice was done by means of powder x-ray diffraction measurement in the temperature range from 20K to the ambient. Magnetic susceptibility measurements were performed by means of SQUID manetometer in the range from the ambient to 4.2K.The spin glass temperatures, Tg, were determined accordingly. In the course of the present study, diffuse intensities due to the short range magnetic ordering was found by the powder neutron diffraction measurement below 100K.The magnetic structure-type of the magnetic clusters, which is responsible for the diffuse scatterings, has been determined by means of single crystal neutron diffraction study. The s … More ingle crystal neutron diffraction measurement was performed in the magnetic field up to 5-Tesla by the use of high resolution neutron diffractometers, HRPD and HERMES installed in the JRR3M reactor hall and the thermal guide hall, respectively. Two dimensional neutron diffraction intensity measurement was performed in the 001 reciprocal plane simultaneously by many neutron counters set in the instruments. Brillouin scattering measurement was tried to study the spin dynamics in the low temperature range. Brillouin scattering measurement, i.e., an optical inelastic scattering measurement, is suitable to measure the excitation levels in the range below 0.5meV with the resolution of 0.01meV.A new Ar-gas laser was purchased with the aid of present financial support and a 5-pass high resolution Fabry-Perot interferrometer was made from an old 3-pass interferrometer, and then a 5-pass Brillouin scattering system was assembled. Brillouin scattering measurement at low temperatures in the magnetic field up to 4000 Oe was successfully performed for the complicated ferromagnetic metallic compound. A part of the magnon dispersion relationship consistent with the neutron scattering data was determined by this instrument. Neutron inelastic scattering measurement has been performed for Zn_<0.6>Mn_<0.4>Te sample using the cold neutron spectrometer AGNES.Critical scattering, associated with the spin glass transition has been observed for the first time in this semimagnetic semiconductor. The critical scattering was observed at temperatures in the vicinity of the spin glass transition temperature, 17K.Photo conductivity has been found also for the first time below 150K in Zn_<0.6>Mn_<0.4>Te sample. The electric AC conductivity has been increased dramaticaly under the laser light with the wave lengths of lambda=6328,5145 and 4880A,respectively. The conductivity was reduced to the original level after the light was darkened, but it took very long, i.e.2000 second at 50K,being above the Less

目前的研究旨在获得光学sennsitive磁簇的结构特性，并且是c-type半导体中c簇的相关特性，该特性与磁性金属原子deped deped。通过标准的Bridgeman方法制备。从范围从周围的范围到4.2k的范围。是由单个晶体中子衍射研究的均值来确定的，这是由单个晶体中子衍射研究确定的。在JRR3M Hall Hall热导体大厅中，在散射测量中设置的许多中子次数同时在001互惠平面中进行了二维TRON衍射强度测量在0.01Mev的分辨率下，在低于0.5mev的范围内，在借助出现的支撑和5次高分辨率的Fabry-perrot干涉仪的帮助下购买了一个新的AR-Gaser，并通过了干扰素SS Brillouin散射系统在磁场中，在磁场上，对磁性金属化合物的散射测量成功地进行了中子散射数据。临界散射，在ine ine ine中观察到自旋玻璃转变。在Zn_ <<Zn_ <<Zn_ <150k的时间里，也发现了Spin Glass Termition Wemportion on Disctitition的温度下的临界散射。 0.4> TE样品。电动AC转换性是巨大的激光光，其长度分别为6328,5145和4880a。