Surface wet-etched Y3Fe5O12 films with perpendicular magnetic anisotropy for ultrahigh density spintronic device applications

Yttrium iron garnet (YIG) film, especially with perpendicular magnetic anisotropy (PMA), is a promising material for energy-efficient spintronic devices due to its extremely low damping constant. However, a poorly crystallized layer tends to form on the top surface of the YIG film during the annealing process, which severely hinders the interfacial spin transport. To overcome this limitation, we developed a surface treatment method using soft phosphoric acid. After the surface wet-etching treatment, both the spin mixing conductance and interfacial thermal conductance between the PMA-YIG film and post-deposited Pt layer can be increased by ~70% and ~100%, respectively. These PMA-YIG films with wet-etched surfaces hold promise for ultrahigh-density spintronic device applications.