An integrated approach to doped thin films with strain-tunable magnetic anisotropy: powder synthesis, target preparation and pulsed laser deposition of Bi:YIG

Abstract

We present a synthesis/processing method for fabricating ferrimagnetic insulator (Bi-doped yttrium iron garnet) thin films with tunable magnetic anisotropy. Since the desired magnetic properties rely on controllable thickness and successful doping, we pay attention to the entire synthesis/processing procedure (nanopowder synthesis, nanocrystalline target preparation and pulsed laser deposition (PLD)). Atomically flat films were deposited by PLD on (111)-orientated yttrium aluminum garnet. We show a significant enhancement of perpendicular anisotropy in the films, caused by strain-induced anisotropy. In addition, the perpendicular anisotropy is tunable by decreasing the film thickness and overwhelms the shape anisotropy at a critical thickness of 3.5 nm.

Keywords

• Perpendicular magnetic anisotropy (PMA)
• ferrimagnetic insulators
• yttrium iron garnet
• nanostructured oxides
• current-activated pressure-assisted densification (CAPAD)
• spark plasma sintering (SPS)