Angular dependence of the anomalous Hall effect in LSMO films


  Netanel Naftalis [1]  ,  Noam Haham [1]  ,  Jason Hoffman [2]  ,  Matthew S. J. Marshall [2]  ,  Charles H. Ahn [2]  ,  Lior Klein [1]  
[1] Department of Physics, Nano-magnetism Research Center, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University
[2] Department of Applied Physics, Yale University

The anomalous Hall effect (AHE) is an intriguing magnetotransport phenomenon linked to various intrinsic and extrinsic mechanisms. While for some conductors quantitative understanding of this phenomenon has been achieved, the understanding of the AHE in the manganites is far from comprehensive.

We measured the transverse resistivity (ρxy) of thin films of La0.8Sr0.2MnO3 at temperatures between 5 to 200 K and magnetic fields up to 9 T as a function of the angle θ between the film normal and the magnetic field. We find that for fields above 4 T, for which the magnetization (M) is practically parallel to the magnetic field, ρxy=Acosθ+Bcos(3θ). The first term is attributed to the ordinary and anomalous Hall effect, and the unexpected cos(3θ) term is attributed only to the anomalous Hall effect. We show that the angular dependence of the longitudinal resistivity, ρxx, and of the magnitude of M cannot explain the existence of a cos(3θ) term. We discuss the implication of this term on the possible mechanisms of the anomalous Hall effect in this compound.