Magnetic and magneto-transport properties of ZnO:Ni films

Magnetic semiconductor (MS), Ni doped ZnO film was fabricated by pulsed laser deposition method on sapphire (0001) substrates. Ni dissolves until View the MathML source into ZnO by low temperature growth technique. Lattice constant c once increases with increasing Ni content and has maximum point at the Ni content of View the MathML source, and then it suddenly decreases. In all the Ni content range, the films exhibits n-type conduction. With increasing the Ni content, the carrier density and mobility decrease. ZnO films with the Ni content range from 3 to View the MathML source exhibit ferromagnetic behavior at View the MathML source. At View the MathML source, the magnetization against applied magnetic field shows superparamagnetic behavior and it maintains at least up to View the MathML source. To study the effect of carrier density, Al was additionally doped. The effect of carrier density and Ni content on the structure, magnetic and magneto-transport behaviors are described.