Structural and magnetic properties of the Zn-Mn-O system

Abstract

Zn-Mn-O semiconductor crystallites with nominal manganese concentration x = 0.01, 0.02, 0.04 and 0.10 were synthesized by a solid state reaction route using oxalate precursors. Thermal treatment procedure was carried out in air at different temperatures in the range 400 - 900 degrees C. The samples were investigated by X-ray diffraction, magnetization measurements and electron paramagnetic resonance. X-ray analysis reveals that dominant crystal phase in the Zn-Mn-O system corresponds to the wurtzite structure of ZnO. Room temperature ferromagnetism, is observed in the Zn-Mn-O samples with lower manganese concentration, x LT = 0.04, thermally treated at low temperature (500 degrees C). Saturation magnetization in the sample with x = 0.01 is found to be 0.05 mu(B)/Mn. The ferromagnetic phase seems to be developed by Zn diffusion into Mn-oxide grains.