Abstract
We have investigated the effect on the optical and magnetic properties of adding W or Co to Bi-substituted garnet films sputtered on glass substrates. Adding a small amount (<1.2 at. %) of W makes the film optically homogeneous. It also increases coercivity more than three times, probably due to wall pinning by W atoms. Adding Co reduces coercivity. On the thin film with added W, we have successfully performed a dynamic thermomagnetic writing with a regular bit shape. This promotes development of magneto-optical memory using garnet sputtered film.