X-ray study of the structure and magnetic properties of ZnO:(Co, Mn) powders

Mn- and Co-doped ZnO powders were prepared by sol-gel method. The XRD peak position shifts regularly with the magnetic-ions concentration of the samples. Magnetism analyzing indicates that Zn(1-x)Mn(x)O is paramagnetic at room temperature, and at low temperature the exchange interaction between Mn ions is antiferromagnetic. Co-doped ZnO is also paramagnetic at room temperature. Ferromagnetic behavior can be found in Zn(1-x)Co(x)O at low temperature (T(c) approximate to 150 K), but the saturation magnetization is only about 0.1 mu(B)/Co, indicating only a fraction of Co ions participate in ferromagnetism and the rest may contribute to the observed paramagnetic signal or even be antiferromagnetic coupled. (c) 2008 Elsevier B.V. All rights reserved.