Significant enhancement of ferromagnetism in Zn${}_{1-x}$Cr${}_x$Te doped with iodine as an n-type dopant

Abstract

The effect of additional doping of charge impurities was investigated in a ferromagnetic semiconductor Zn${}_{1-x}$Cr${}_x$Te. It was found that the doping of iodine, which is expected to act as an n-type dopant in ZnTe, brought about a drastic enhancement of the ferromagnetism in Zn${}_{1-x}$Cr${}_x$Te while the grown films remained electrically insulating. In particular, at a fixed Cr composition of x = 0.05, the ferromagnetic transition temperature Tc increased up to 300K at maximum due to the iodine doping from Tc = 30K of the undoped counterpart, while the ferromagnetism disappeared due to the doping of nitrogen as a p-type dopant. The observed systematic correlation of ferromagnetism with the doping of charge impurities of both p- and n-type, suggesting a key role of the position of Fermi level within the impurity d-state, is discussed on the basis of the double exchange interaction as a mechanism of ferromagnetism in this material.

5 figures, to be published in Phys. Rev. Lett

Cited by in corpus (5)

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• X-ray magnetic circular dichroism and photoemission study of the diluted ferromagnetic semiconductor Zn${}_{1-x}$Cr${}_x$Te
• Electronic structure of Ga${}_{1-x}$Cr${}_x$N and Si-doping effects studied by photoemission and X-ray absorption spectroscopy