The growth of an epitaxial Mg-Al spinel layer on sapphire by solid-state reactions

• Main Authors: Chun-Jen Chen, 陳俊任
• Other Authors: Jyh-Chen Chen
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/71461647940292610570

碩士 === 國立中央大學 === 機械工程研究所 === 93 === In this study, an epitaxial Mg-Al spinel layer was successfully grown on a sapphire single crystal surface using solid-state reactions. The processes of solid-state reactions with PVD and heat treatment were applied to grow epitaxial layer with preferred orientation. And the layer composition and structure can be confirmed by the further analyses. Through the controlling of the heat treatment parameters, the variation of compositions and properties influenced by different conditions on surface layer had been discussed. From the experiment results, reaction layer showed different reaction rate with various heat treatment, and it was proportion to the temperature and duration. In additional, the orientation of epitaxial Mg-Al spinel layer would depend on the cut of sapphire substrate. The hhh-type orientated spinel layer preferred to grow on C- and A-plane sapphire, and the hh0-type orientated spinel layer preferred to grow on M-plane sapphire. Simultaneously, the in-plane orientation relationship between spinel epitaxial layer and sapphire substrate could be obtained by φ scan. The morphology of the epitaxial spinel layer surface will present a particular three-fold symmetrical structure by scanning electron microscope. The model of atomic arrangement was employed to explain the relationship between the surface morphology of spinel and its miller index.