Structural and magnetic properties of Fe–Al2O3 films

Abstract We report a study on the structural and magnetic changes of Fe–Al 2 O 3 films co-deposited at room temperature and subsequently annealed at 400°C during 5 h. It is found that the annealing produces a better interface between the Fe clusters and the Al 2 O 3 matrix, giving an increase in the magnetoresistance (MR) effect. Interesting is the bias dependence of MR. For low bias, below 2.5 V, the MR is negative and becomes positive for bias above 2.5 V. This effect can be ascribed to an inversion of the spin of tunneling electrons.