Ferromagnetic and Transport Properties of Mn-Doped ZnO

Crystalline structure and the magnetic and the transport properties of MnZnO bulk and thin films were investigated. For all MnZnO samples, ferromagnetism was observed above room temperature. All films exhibited Mn3O4 and ZnMn2O4 second phases. The temperature dependences of the field-cooled (FC) and the zero-field-cooled (ZFC) magnetizations showed transitions near 50 K and 270 K, respectively. These transitions could be coming from Mn3O4 and MnZn2O4. The ferromagnetism above room temperature in the MnZnO films could be due to ZnMn2O4, but the ferromagnetism is coming from Zn1-xMnxO in the range from 50 K to 270 K and mainly from Mn3O4 at temperatures below 50 K. The magnetoresistance (MR) data showed a positive curvature below 30 K and a negative curvature at 70 K. This behavior indicates that some of the ZnO is replaced by Mn. KCI Citation Count: 11