Magnetotransport and magnetic properties of p-Zn1-xMn xTe:N - Carrier-induced ferromagnetism

Abstract

The magnetic properties of nitrogen-doped p-Zn1-xMn xTe grown by MBE were studied through the magnetotransport measurements. In a sample of p-Zn1-xMnxTe with x = 0.034 and p = 4.7 × 1019 cm-3, a hysteresis loop was observed below 2.5 K in the Hall resistance and the magnetoresistivity, which indicates the ferromagnetic transition. From the plot of (R Hall/Rsheet)2 against B/(R Hall/Rsheet) at several temperatures, which corresponds to the so-called Arrott plot, we can estimate the Curie temperature (T c) of the sample as about 3K, suggesting that this sample has the higher Tc than ever reported. We also demonstrated, by means of light irradiation, that the strength of ferromagnetic interactions can be controlled by changing the hole concentration. An increase of the ferromagnetic behaviours such as a small increase of the coercive field was observed under light irradiation. This result strongly supports that the ferromagnetic transition in Zn1-xMnxTe is the carrier-induced one. © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.