Constant-current-density model for the anomalous Hall effects in Hg0.8Cd0.2Te

Abstract

This letter presents a simple model developed for calculating the Hall coefficient and Hall mobility in inhomogeneous narrow-band-gap semiconductors, including inclusions with opposite conduction type. The model is based on one assumption that the current density is a uniform constant in the sample in spite of the inhomogeneities. This assumption is supported by a variational calculation based on the principle of least entropy production rate. The model is then applied to explain the anomalous Hall data in the n-type Hg0.8Cd0.2Te, and a good fit is obtained when p-type Hg0.8Cd0.2Te is considered to be the inclusions. The results show that some assumptions in a previous layer model are not necessary in order to explain the observed phenomena. By using this simplified treatment of material inhomogeneity, it will be easier to design experiments to investigate the cause of such inhomogeneity.

Special Technique for Growing Tl4S3, Anisotropy of Electrical Conduction and Photophysical Properties

“…The measured Hall coefficient was interpreted by taking the volume fraction and the Hall coefficient of the p-type domain into consideration. The observed anomalous temperature dependence of mobility at high temperature in the present Tl 4 S 3 crystals together with its order-of-magnitude lower value as compared to earlier results may be due to different features of the microstructure as the formation of p-type domains during the crystal growth stage . This interpretation also supports an explanation given by Nagat 22 since the parasitic phases in the form of inclusions are expected to result in new localized states.…”

“…An anomalous behavior of the temperature dependence of Hall mobility similar to what has been observed in the present work has also been reported by Nagat in highly resistive thallium monosulfide single crystals, and it is proposed to be due to a change in transport mechanism between localized states either within the energy gap or in the regions close to the band edges. On the other hand, anomalous behavior of the Hall data for HgCdTe layers was reported in the literature and a model has been proposed in which a narrow band gap material having inclusions of the opposite conduction type was considered …”

Analysis of magnetic field dependent Hall data in narrow bandgap Hg1−xCdxTe grown by molecular beam epitaxy

“…[1][2][3]19,20 It is in these particular cases that the hybrid approach of MS analysis combined with MCF becomes not only appropriate, but necessary in order to extract the transport parameters in an unambiguous way. Throughout the course of this study, a large number of samples were analyzed which displayed the ''classical'' Hall characteristics normally associated with either n or p-type HgCdTe.…”

“…[2][3][4][5][6][7][8][9] However, during the past decade it has been shown that such anomalous Hall characteristics can be explained by one of at least three different mechanisms not related to the energy spectrum ͑see review by Ivanov-Omskii et al 10 and references therein͒. The first possibility is the presence of microinhomogeneities in the HgCdTe crystal which may be of technological origin.…”