Structure, magnetic and electronic properties in Ga doped α-Cr2O3 oxide

Abstract

The samples of Ga doped Cr2O3 oxide have been prepared using chemical co-precipitation route. X-ray diffraction pattern and Raman spectroscopy have confirmed rhombohedral crystal structure with space group R3¯C in the samples. Magnetic measurement of the samples in the temperature range 5K-350 K has indicated the dilution of antiferromagnetic (AFM) spin order in Ga doped α-Cr2O3 system. Further, the antiferromagnetic ordering temperature at about 320 K in bulk α-Cr2O3 oxide has been suppressed in Ga doped α-Cr2O3 system that exhibited signature of ferrimagnetic behavior. Small grain size effect of the samples has dominated magnetic features at lower temperatures by exhibiting superparamagnetic type behavior of surface spins. The current-voltage (I-V) curves of the Ga doped samples have shown highly non-linear behavior and exhibited many unique features, especially hysteresis loop with two irreversible electronic states and negative differential resistance (NDR).