Impact of Cr doping on Hall resistivity and magnetic anisotropy in SrRuO3 thin films.

Abstract

Hall effects, including anomalous and topological types, in correlated ferromagnetic oxides provide an intriguing framework to investigate emergent phenomena arising from the interaction between spin-orbit coupling and magnetic fields. SrRuO3 is a widely studied itinerant ferromagnetic system with intriguing electronic and magnetic characteristics. The electronic transport of SrRuO3 is highly susceptible to the defects (O/Ru vacancy, chemical doping, ion implantation), and interfacial strain. In this regard, we investigate the impact of Cr doping on the magnetic anisotropy and the Hall effect in SrRuO3 thin films. The work encompasses a comprehensive analysis of the structural, spectroscopic, magnetic, and magnetotransport properties of Cr-doped SrRuO3 films grown on SrTiO3(001) substrates. Cross-sectional transmission electron microscopy reveals a sharp and coherent interface between the layers. Notably, perpendicular magnetic anisotropy is preserved in doped films with thicknesses up to 113 nm. The resistivity exhibits a T^2 dependence below the Curie temperature, reflecting the influence of disorder and correlation-induced localization effects. Interestingly, in contrast to the undoped parent compound SrRuO3, an anomaly in the Hall signal has been observed up to a large thickness (56 nm) attributed to the random Cr doping and Ru vacancy. Based on our measurements, a field-temperature (H -T) phase diagram of anomalous Hall resistivity is constructed.