Influence of crystallographic anisotropy of unsaturated yttrium iron garnet film on spin injection in platinum film by the mechanism of inverse spin Hall effect

Background and Objectives: Thin-film structures of yttrium iron garnet ferrite film – platinum are actively studied due to the possibility of using the direct (for converting electric current in platinum into spin waves in ferrite) and inverse (injection of spin current from ferrite into platinum film) spin Hall effects for application in magnonics and spintronics devices. Materials and Methods: The structures studied in this work were obtained on the basis of yttrium iron garnet films of crystallographic orientations (100) and (111), from which waveguides were cut out, in which spin waves were excited. Their propagation was monitored using a vector network analyzer. A platinum film in the form of stripe oriented along the long axis of the waveguide was fabricated on the surface of the waveguides using magnetron sputtering, photolithography, and ion etching. Spin injection from ferrite film in the platinum film results in electric charge current generation. An experimentally measured value was the electromotive force between contacts to the platinum stripe. It was measured using a synchronous detector. The measurements were carried out at magnetization field values lower than the saturation field of the ferrite film, with the magnetic structure of the film being divided into domains. Results and Conclusions: It has been shown that for both crystallographic orientations the maximum spin injection is achieved when magnetizing the waveguides along the easy magnetization axis and symmetrical domain structure is formed.