Post-annealing effect of YIG ferrite thin-films epitaxially grown by reactive sputtering

Abstract

Amorphous Y–Fe–O ferrite thin-films were deposited on GGG (111) substrates using reactive RF magnetron sputtering with a Y2.84Fe5.16O12 ferrite sintered target. After that, the thin-films were post-annealed in air at temperatures higher than 650 degrees Celsius for 3 hours to be crystallized. In the XRD diagrams, large diffraction peaks from only YIG ferrite (444) or (888) plane were observed in the samples post-annealed at over 1050 degrees Celsius. The half value width (Δθ50) in the rocking curve for YIG ferrite (888) was as small as 0.13 degrees. These results proved that the YIG ferrite films have been grown in hetero-epitaxial manner on GGG (111) substrate with high orientation. The YIG ferrite thin-films had reasonable saturation magnetization of 1.7 kG, relatively low coercivity of less than 5 Oe and small ΔH of around 70 Oe. The YIG ferrite thin-films are useful for microwave magnetic devices. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)