Journal of Magnetism and Magnetic Materials 316, e674 (2007)
Proceedings of the Joint European Magnetic Symposia
Y.F. Chen, M. Ziese and P. Esquinazi
Magnetite films were deposited on Nb-doped SrTiO3 substrates by pulsed laser deposition. The current–voltage characteristics were measured perpendicular to the interface. Strongly nonlinear, asymmetric current–voltage curves were observed. The resistance shows a crossover from insulating to metallic behavior for increasing voltages. The data can be neatly scaled using a scaling approach based on a quantum critical transition theory. This shows that a scaling analysis is clearly insufficient to conclude on the existence of a bulk-like metal/superconductor–insulator transition.