Magnetic and optical properties of Zn_1-xMn_xO thin films prepared by using ultrasonic spray pyrolysis

Diluted magnetic semiconductor Zn_1-xMn_xO (x = 0.05) thin films were prepared using ultrasonic spray pyrolysis. The films were additionally doped with nitrogen in order to obtain a p-type conductivity. Aqueous solutions of zinc acetate (0.5 mol/1), manganese acetate (0.5 mol/1) and ammonium acetate (2.5 mol/1) were used as sources of Zn, Mn and N, respectively. The hole concentration in the nitrogen-doped films was in the range of 10¹⁵ - 10¹⁸ cm^-3 at room temperature. The dependence of the magnetization on the magnetic field (M-H) for the highly nitrogen-doped Zn_0.95Mn_0.05O sample showed a hysteresis loop at low temperatures. A Curie temperature of around 80 K for the sample with a hole concentration of 10¹⁸ cm^-3 was determined from the temperature dependence of the magnetization.