Ferromagnetism in Ti-Doped ZnO Nanoclusters Above Room Temperature

Ferromagnetism is observed at room temperature, when a small percentage (5%) of nonmagnetic titanium is added to zinc atoms to form Ti-doped ZnO nanoclusters in the oxygen atmosphere. The nanocluster films are prepared at room temperature by a technique that is a combination of high-pressure magnetron sputtering with aggregation. A Superconducting Quantum Interference Device (SQUID) measures the magnetic properties of this cluster films at various temperatures. Ti dopant exhibits +4 oxidation state through out the cluster film. Coercivity of the samples decreased exponentially with the increase of temperature