Microstructures and Magnetic Properties of Single-Step Deposited Ce:YIG/YIG Bilayer Films With Different Layer Thickness Ratios

Cerium-substituted yttrium iron garnet (Ce:YIG) thin films are promising magneto-optical (MO) materials for the application in optical isolators. Ce:YIG can be grown on the YIG seed layer, and the change of layer thickness ratio for Ce:YIG to YIG may result in different magnetic properties. In this work, Ce:YIG (Ce1Y2Fe5O12) to YIG (Y3Fe5O12) bilayer films, with different thickness ratios of 2:1, 4:1, 6:1, and 8:1, were grown by pulsed laser deposition (PLD); 2:1 and 4:1 films consist of pure YIG phase; 6:1 and 8:1 films consist of YIG phase, Y2Fe4O9 phase with hexagonal structure, and Y2O3 phase with cubic structure. Y2Fe4O9 and Y2O3 phases induce the decrease of saturation magnetization (
$M_{s}$
). The concentration of Fe2+ and Ce4+ ions increases with layer thickness ratio increasing, resulting in the decrease of saturation magnetization (
$M_{s}$
), coercivity (
$H_{c}$
), and magnetic anisotropy energy (
$E$
). It is found that the best magnetic properties, including
$H_{c}$
(26.9 Oe),
$M_{s}$
(140.6 emu/cm3), and
$E$
(257.5 J/cm3), are obtained in the 2:1 film.