Magnetic and electrical properties of p-type Mn-doped CuCrO2 semiconductors

Mn-doped CuCrO2 polycrystalline semiconductors were synthesized by the sol-gel method. The valence state of the Mn ions in the CuCr1-xMnxO2 samples was identified as 3+ by analysing their lattice parameters, their electrical properties and their x-ray photoelectron spectra. The temperature dependence of the susceptibility of all samples exhibits paramagnetic behaviour at high temperature. For x = 0.20 the samples exhibit a clear ferromagnetic ( FM) transition at 120 K. Clear hysteresis loops indicate that FM order exists in the Mn-doped samples at 50 K. All samples behave like semiconductors. The electrical and magnetic properties indicate that the ferromagnetism can be attributed to the double exchange interaction between the Mn3+ and Cr3+ in CuCr1-xMnxO2 semiconductors.