ELECTRONIC AND MAGNETIC-PROPERTIES OF THE DILUTED MAGNETIC SEMICONDUCTOR HG1-XMNXTE1-YSEY

Electrical resistivity, Hall coefficient and magnetoresistance for dil uted magnetic semiconductor Hg1-xMnxTe1-ySey crystals with y = 0.01 an d x = 0.03, 0.06, 0.14, 0.30 have been measured in the temperature ran ge 4.2-300 K and in magnetic fields up to 7 T. Negative magnetoresista nces are observed at 4.2 K in all samples, which can be explained by t he change of the acceptor activation energy in the magnetic field. The temperature and magnetic field dependences of the Hall coefficient an d its sign reversal in a magnetic field can be explained quantitativel y by the coexistence of three group of carriers, electrons and two typ es of holes with different mobilities. Magnetic susceptibility measure ments using a SQUID, magnetometer in the temperature range 4.2-80 K re veal that these solid solutions show a paramagnetic behaviour and the sample with x = 0.30 exhibits a spin-glass transition at a temperature lower than that of Hg1-xMnxTe with the same Mn content.