Effects of electron localization in V2 − y O3

The effect of nonstoichiometry on the metal-insulator phase transition in V₂O₃ is studied. It is established that an increase in the vanadium deficiency in V2 ? yO₃ brings about a shift in the phase transition temperature toward lower temperatures and an increase in the width of the temperature hysteresis loop of the electrical conductivity. As the vanadium deficiency increases to a level corresponding to the composition ～V_1.974O₃, the phase transition completely disappears and the sample remains metallic down to T = 1.6 K. The magnetoresistance is measured for samples of this composition in longitudinal and transverse magnetic fields at T = 4.2 K.