Synthesis and characterization of TM-doped CuO (TM = Fe, Ni)

Polycrystalline Cu1-xTMxO samples (x = 0 and 0.06; TM = Ni2+ and Fe3+) were grown using a co-precipitation method. The structural and magnetic properties were investigated by means of temperature dependent magnetic susceptibility and room temperature X-ray powder diffraction (XRPD). The XRPD analyses of the samples reveal the formation of single phase with structure isomorphous to the CuO. Interestingly, T-dependent magnetization shows the reduction of Neel temperature, T-N, from 213 K in the copper oxide to 70 K in the Fe-doped sample (x = 0.06). Because in the Ni-doped samples TN seems to be unaffected, this decrease in TN is believed to be due to the different electronic structure of the dopant. The ferromagnetic behavior observed at room temperature in all samples can be related to both the level of oxygen (excess or vacancy) of our samples and to the difference in the magnetic structure of the dopant. (c) 2008 Elsevier B.V. All rights reserved.