| Summary: | 碩士 === 元智大學 === 化學工程與材料科學學系 === 104 === In this study, Si3N4(20 nm)/PrFeB+Fe(50-250 nm)/Si3N4(50 nm)/glass films with different Fe content are deposited by RF magnetron sputter using Pr25Fe65B10 alloy target and pure Fe chips. The effects of Fe content on magnetic properties and microstructures are analysis by VSM, SEM, XRD, TEM and EDS, in order to realize the proper composition of PrFeB alloy targets for sputtering high performance Pr-Fe-B thin films.
In this investigation, it is observed that the Pr-Fe-B particle size decrease and the saturation magnetization (Ms) increase with increasing the Fe content. Phase structure showed the low coercivity (Hc) is due to the less hard Pr2Fe14B phase. The metallic Pr2Fe23B3 phase declined Hc when in high Fe content samples. It is found that the Fe in PrFeB thin film diffuse into Si3N4 underlayer, forming Fe-rich FeSi alloy film as the underlayer to promote perpendicular magnetic anisotropy (PMA) Pr-Fe-B growth. The maximum Hc appears at Fe=75.53 at.% and the highest PMA is obtained at Fe=72.18 at.%. In this study, the high perpendicular magnetic properties may exist when Fe composition is ranged from 72 to 75 at.%.
It is observed that the roughness decrease with decreasing the thickness of the Pr-Fe-B thin films and increasing the Fe content. The Hc is similar in all thinner case of thin films, eventually the Fe content is different. It may due to the short diffusion length enhance the mobility of Fe atoms and promote the formation of Pr2Fe14B phase, the effect of the Fe content of films toward to Hc be will reduced when the thickness of the Pr-FeB thin decrease.
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