Negative Magnetoresistance Effect in Pb1-xMnxTe(Cr)and Pb1-xMnxTe(Yb)

摘要

We report on the observation of a strong negativemagnetoresistance effect in Pb1-xMnxTe(Yb) and Pb1-xMnxTe(Cr) at lowtemperatures. The main features of the effect are analogous in both cases.The sample resistance at the liquid helium temperature quickly drops (by～～ 3 orders of magnitude in Pb1-xMnxTe(Yb), and by ～ 30% inPb1-xMnxTe(Cr)) when the magnetic field increases up to 5-6 T, withsubsequent rise as the field increases to 17.5 T. The effects observed aredefined by specifics of conductivity via the impurity band. They mostlikely originate from the shift of the chemical potential with respect to themobility edge in the impurity band in a magnetic field.