Magnetic and magneto-otpical properties of Ca-doped Bi-YiG sputtered films

Bismuth substituted iron garnet (Bi-YIG) is very attractive material for magneto-optical media and has been applied in magneto-optical devices working in the infrared wavelength region. However, in the visible wavelength region, Bi-YIG shows large absorption because of Fe³⁺, then the figure of merit is considerably smaller than that in the infrared wavelength region. We have investigated Ca-doped Bi-YIG to improve the optical absorption in this system for the use in the visible wavelength region. In this paper, we describe annealing properties of highly Ca-doped Bi-YIG sputtered films. The films are examined with regard to microstructural, magnetic and optical characteristics.