Electrical generation and detection of spin waves in polycrystalline YIG/Pt grown on silicon wafers

Abstract

We studied the magnetic properties of polycrystalline Y _3 Fe _5 O _12 (YIG) thin films (less than 100 nm) deposited on thermally oxidized silicon wafer by magnetron sputtering and followed by the post-annealing process. Our ferromagnetic resonance (FMR) results demonstrate that sputtering at room temperature combined with the post-annealing treatment can be an efficient method to achieve large-area (inch scale) and highly uniform YIG thin films with a low damping constant α ∼ 7 × 10 ^−3 on cheap oxidized Si wafer. Furthermore, our spin pumping experiments demonstrate that the polycrystalline YIG/Pt system has a good spin mixing conductance, where spin current can be effectively injected into the adjacent Pt layer from YIG through the interface. Then the electrical detection of magnetic properties (e.g., spin waves) of insulating YIG film can be achieved via the inverse spin Hall effect of Pt. The electrical detection of spin waves in the large-area polycrystalline YIG/Pt on silicon wafer may help to develop new spintronic devices (e.g., magnon-based devices) by utilizing the complementary metal-oxide-semiconductor (CMOS) technology.

Keywords

• spin pumping
• magnetron sputtering
• polycrystalline YIG film
• ferromagnetic resonance
• spin current detection