Chemical composition, microstructure and magnetic characteristics of yttrium iron garnet (YIG, Ce : YIG) thin films grown by rf magnetron sputter techniques

YIG thin films were grown by rf magnetron sputter techniques, We investigat ed the effect of post-deposition heat-treatment as well as various depositi on parameters such as substrate materials, substrate temperature, sputter p ower, and sputter gas types on the crystallinity, chemical composition, mic rostructure and magnetic characteristics of the films, Post-deposition heat -treatment over 750 degrees C was applied to crystallize as-prepared amorph ous films, and a strong tendency of particular crystallographic planes lyin g parallel to substrate surface was observed for the heat-treated film on G GG substrate. The chemical composition of the film exhibited a wide range o f chemical stoichiometry depending on the oxygen fraction of the sputter ga s, and in particular the compositions of the YIG and Ce:YIG films deposited in sputter gas with an oxygen fraction of 20% were Y2.88Fe3.84O12 and Ce0. 24Y1.10Fe3.50O12, respectively. With raising the temperature of post-deposi tion heat-treatment from 900 degrees C to 1100 degrees C,the surface roughn ess of the film on GGG substrate increased, but coercive force as well as f erromagnetic resonance line width decreased.