Study of the Phase Transformation of Single Particles of Ga2O3 by UV‐Raman Spectroscopy and High‐Resolution TEM |
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Authors: | Xiang Wang Dr. Qian Xu Dr. Fengtao Fan Dr. Xiuli Wang Dr. Mingrun Li Prof. Zhaochi Feng Prof. Can Li |
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Affiliation: | 1. State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy, 457 Zhongshan Road, Dalian 116023 (P.?R. China), Fax: (+86)‐411‐84694447;2. Graduate University of Chinese Academy of Sciences, Chinese Academy of Sciences, No.19A Yuquan Road Beijing, 100049 (P.?R. China) |
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Abstract: | By taking advantage of UV‐Raman spectroscopy and high‐resolution TEM (HRTEM), combined with the focused ion beam (FIB) technique, the transformation from GaOOH into α‐Ga2O3 and then into β‐Ga2O3 was followed. We found that the stepwise transformations took place from the surface region before developing into the bulk of single particles without particle agglomeration and growth. During the transformation from GaOOH into α‐Ga2O3, the elimination of water vapor through the dehydroxylation of GaOOH resulted in the formation of micropores in the single particles, whilst maintaining their particle size. For the phase transformation from α‐Ga2O3 into β‐Ga2O3, the nucleation of β‐Ga2O3 was found to occur at the surface defects and this process could be retarded by occupying these defects with a small amount of La2O3. By finely controlling the process of the phase transformation, the β‐Ga2O3 domains gradually developed from the surface into the bulk of the single particles without particle agglomeration. Therefore, the surface structure of the α‐Ga2O3 single particles can be easily tuned and a particle with an α@β core–shell phase structure has been obtained. |
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Keywords: | core– shell structures gallium microporous materials phase transitions Raman spectroscopy |
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