Effect of crystalline quality and substitution on magnetic anisotropy of SrRuO3 thin films

Magnetic anisotropy of pure and substituted laser-ablated SrRuO3 and SrRu0.9Cr0.1O3 thin films has been studied by rotational magnetization experiments in a superconducting quantum interference device (SQUID) magnetometer. The magnetic easy axis for epitaxial (single domain) SrRuO3 and SrRu0.92O3 thin films lies in the (001) plane and is tilted away from the normal to the surface by 23°-26°. Its direction lies between the [110] and [010] axes. For the lower oxygen pressure grown SrRuO3 thin film, which consists of intertwined crystal nanodomains the magnetic easy axis is no longer locked-in to the (001) plane but is oriented closer to the normal to the surface that is the resultant orientation of easy axes for different domains. Similar effect is observed in single-domain SrRu0.9Cr0.1O3 thin film with random Cr substitution on the RuO6 octahedra. A role of ruthenium deficiency observed in all the studied thin films is also discussed.