Structure and magnetic properties of Mn-doped ZnO semiconductors

Mn-doped zinc oxide (Zn1−xMnxO) powders were synthesized from Zn nitrate and Mn nitrate reduced with citrate, with x varying from 0.01 to 0.08. X-ray diffraction (XRD) and high resolution transmission electron microscope (HRTEM) analysis revealed that Mn ions were substitutionally well incorporated into the crystal lattice of ZnO for all samples. The magnetization follows the Curie–Weiss law at high temperature and the samples are still paramagnetic down to 5 K. The negative value of dominant exchange integral between the nearest magnetic ions indicates antiferromagnetic interaction between Mn ions in the Zn1−xMnxO.