Amorphous Y-Fe-O ferrite thin-films were deposited on GGG (111) substrates using reactive RF magnetron sputtering with a Y 2.84 Fe 5.16 O 12 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 postannealed at over 1050 degrees Celsius. The half value width (∆θ 50 ) 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 ∆H of around 70 Oe. The YIG ferrite thin-films are useful for microwave magnetic devices.

PACS 75.50.Gg, 75.70.Ak, For epitaxial growth of YIG films by sputtering, methods of both direct growth and solid phase epitaxy (SPE) were used. However, it was very hard to sputter at high temperature for the direct growth of epitaxial YIG films. Instead, the SPE is a very useful and easy method for growing YIG epitaxial films. It was very effective to add a small amount of oxygen to suppress the formation of the YFeO 3 phase in the SPE. The crystallization temperature of the Fe -Y -O amorphous films on GGG (111) substrate was much lower than that of Fe -Y -O powder. An excellent epitaxial growth of YIG films could be confirmed with XRD by both very high intensities and very low values of the full width at half maximum of the YIG (888) plane. It could be seen that it is necessary to anneal the films at higher temperature for excellent epitaxy. The films annealed at higher temperature shows M -H loops with perpendicular anisotropy which was due to 0.15% lattice mismatch between YIG and GGG.

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