Extraordinary Hall effect in and thin films
Department of Physics and Astronomy, University of Sheffield
Sheffield S3 7RH, UK
Accepted: 9 November 1998
The Hall effect of La0.7Ba0.3MnO3 and La0.7Ca0.3MnO3 thin films was measured in magnetic fields T and for temperatures 10 K 340 K. In the ferromagnetic phase the slope of the Hall resistivity at zero magnetic induction rapidly increases with temperature until a maximum is reached at the Curie temperature TC. A detailed comparison of the Hall resistivity with the magnetization facilitates the separation of the ordinary and extraordinary Hall effect. The ordinary Hall constant RH shows a jump below TC. The extraordinary Hall constant RA scales with the zero-field resistivity. At low temperatures we find a quadratic dependence of RA on the resistivity crossing over to a linear dependence at higher temperatures. Whereas the quadratic scaling law in the ferromagnetic phase can be explained by a conventional side-jump mechanism, the linear dependence near TC and in the hopping regime is inconsistent with conventional skew scattering. The data are compared to a recent theory of the Hall effect in double-exchange ferromagnets.
PACS: 73.50.Jt – Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects) / 75.50.Cc – Other ferromagnetic metals and alloys / 75.70.Ak – Magnetic properties of monolayers and thin films
© EDP Sciences, 1999