Chemical epitaxial growth of nm-thick yttrium iron garnet films with low Gilbert damping

Nanometer-thick Y 3 Fe 5 O 12 (YIG) films with very low damping constant have been fabricated on gadolinium gallium garnet substrates using chemical metal-organic decomposition method. Both the microstructure and ferromagnetic properties of the YIG thin films have been studied. High resolution X-ray diffraction result displayed an epitaxial structure of the YIG film. Surface morphology was investigated using an atomic force microscopy. The average surface roughness is about 0.8 ± 0.2 nm for a ∼50 nm thick epitaxial growth YIG film, which is comparable to the result of pulse laser deposition grown films. The coercivity field of the YIG film is around 1.5 Oe. Furthermore, magnetization dynamics properties were studied using a coplanar waveguide vector-network-analyzer ferromagnetic resonance spectrometer. The extracted damping constant is as low as 1.4 × 10 −3 . The results show that high quality nanometer YIG films can be obtained through chemical epitaxial growth method. It would be very useful for the garnet based spintronics applications.