HgMnTe磁性半导体研究概述

HgMnTe是一种典型的Mn基Ⅱ-Ⅵ族窄禁带磁性半导体材料,已成功应用在红外发光和光电探测领域.同时由于磁性元素Mn的引入,HgMnTe材料中存在两类重要的磁交换作用:d-d交换和sp-d交换,导致HgMnTe具有诸如自旋玻璃转变、(巨)负磁阻、磁场诱导绝缘体-金属相变、巨Faraday旋转效应、光致磁化效应和磁极化子...     

Annealing studies of undoped Hg1−xMnx Te bulk crystals at high temperatures

The effect of high temperature annealing treatments in varying mercury atmospheres on Hg_1−xMn_xTe crystals with long wavelength infrared/very long wavelength infrared cut off wavelengths has been studied. The undoped Hg_1−xMn_xTe crystals were grown using the traveling heater method with a tellurium solvent zone, and composition was verified by infrared transmission measurements. The crystals were subjected to annealing temperatures of 500 and 550°C under mercury pressures varying from Hg-rich conditions to Te-rich conditions. The samples were either air cooled or water cooled to room temperature. Hall effect measurements were carried out at 77K at magnetic fields varying from 500 Gauss to 10 kGauss. The hole concentration in the annealed crystals was found to be roughly inversely proportional to the partial pressure of Hg indicating that the material is essentially intrinsic at the anneal temperature. A defect model and a relationship between the mass action constants for the native acceptor defects of HgMnTe are presented.