The Study of Structural Phase Transitions Mechanism from Würtzite and Zincblende to Rocksalt Structure under High Pressure

• Main Authors: Yu-Ker Chern, 陳余各
• Other Authors: Yuen-Wuu Suen
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/01651677956496547900

博士 === 國立中興大學 === 物理學系所 === 103 === Abstract High-pressure experiment, including three of the optoelectronic semiconductor materials like indium arsenide, oxidized zinc- manganese, and cadmium sulfide, was conducted with diamond anvil cell and Synchrotron Radiation X-ray. And the result is compared with the previous research findings and discussed phase transition pressure and path. The experiment firstly inquires structural change of sample under high pressure and defines its lattice parameter with powder diffraction. As a result, based on the result of the three-sample experiment, this study is to inquire system performance of semiconductor compound under high-pressure transition and structure. These three semiconductor materials are classified as zincblende and wurtzite structure respectively. Experiment undergoes under at most 13.8 GPa, where the result of X-ray diffraction experiment shows three semiconductor materials all have structure transitions. In this experiment, the transition pressure of cadmium sulfide is the lowest, while that of the oxidized zinc-manganese is the highest. These three materials all have the same phenomenon that transition of miscibility coexists in high-pressure phase and low-pressure phase. In applied process, the three axis–compressibilities of wurtzite structure shows not equivalently and anisotropy, while that of zincblende structure shows equivalently and isotropy. The outcome of Raman spectra experiment displays that changing tendency of InAs vibration mode appears discontinuously at approximate 7.8 GPa, which is verified as the transition pressure of InAs metallization. The result of this study indicates the intermediate phase doesn’t appear in the process of the transition of zincblende structure, while the experimental result of wurtzite structure, whose high-pressure structure follows the path of hexagonal system and transforms from B4 structural phase transition to B1 structural phase transition, generally corresponds to the prediction of the theory.