Effect of magnetic dilution in Zn1−xMnxGa2Se4 (0&amp;lt;x&amp;lt;0.5)

M C Morón,S Hull

doi:10.1063/1.1944220

Abstract

The profound effect of magnetic dilution in Zn1−xMnxGa2Se4 with 0&lt;x&lt;0. 5 is demonstrated by the analysis of neutron powder diffraction and magnetic susceptibility data. All the members of the series show a defective stannite crystal structure and a random distribution of the Mn ions. The magnetic archetype system of Zn1−xMnxGa2Se4 with 0&lt;x&lt;0. 5 is not found to be MnGa2Se4 (the magnetic end member of the series with I4¯ symmetry) but, instead, a hypothetical compound with I4¯2m symmetry. The distance between the Mn ions along the various magnetic superexchange pathways is not seriously affected by the degree of dilution. However, the global magnetic interaction between manganese ions is found to be significantly higher than that expected for the classical magnetic dilution of the parent MnGa2Se4. A generally applicable method for the calculation of the correct Weiss temperature θ in diluted magnetic semiconductors is provided.

Highlights

The combination of two or more apparently independent areas of research often leads to valuable observations
ZnGa2Se4 crystallizes in the tetragonal space group I42m possessing a defective stannite structure14 with a = 5.511 7͑3͒ Å and c = 10.964 3͑6͒ Åsee Fig. 1͒
The magnetically undiluted system corresponding to Zn1−xMnxGa2Se4 with 0 Ͻ x Ͻ 0.5 is not MnGa2Se4 but, rather, a hypothetical compound for which the magnetic atoms are distributed at random over the 4d lattice sites of space group I42m with 50% occupancy

Summary

Introduction

The combination of two or more apparently independent areas of research often leads to valuable observations. This is the case for diluted magnetic semiconductorsDMSs. This is the case for diluted magnetic semiconductorsDMSs Within these materials a given concentration of a magnetic element is introduced into a nonmagnetic semiconductor matrix. One of the problems encountered in DMSs is that most of these systems, pseudobinary DMSs, exhibit comparatively higher ␪ values.. One of the problems encountered in DMSs is that most of these systems, pseudobinary DMSs, exhibit comparatively higher ␪ values.10 This makes the calculation of reliable Weiss temperatures more difficult due to experimental limitations on the available temperature range In most DMSs the arrangement of the magnetic atoms is random. As a consequence, many variables follow a linear dependence versus the content of the magnetic cations, as is the case of the Weiss temperature. One of the problems encountered in DMSs is that most of these systems, pseudobinary DMSs, exhibit comparatively higher ␪ values. This makes the calculation of reliable Weiss temperatures more difficult due to experimental limitations on the available temperature range

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Conclusion