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Báo cáo hóa học: " Crystalline Gaq3 Nanostructures: Preparation, Thermal Property and Spectroscopy Characterization"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Crystalline Gaq3 Nanostructures: Preparation, Thermal Property and Spectroscopy Characterization | Nanoscale Res Lett 2009 4 820-827 DOI 10.1007 s11671-009-9321-y NANO EXPRESS Crystalline Gaq3 Nanostructures Preparation Thermal Property and Spectroscopy Characterization Ya-Wen Yu Chun-Pei Cho Tsong-Pyng Perng Received 25 February 2009 Accepted 8 April 2009 Published online 30 April 2009 to the authors 2009 Abstract Crystalline Gaq3 1-D nanostructures and nanospheres could be fabricated by thermal evaporation under cold trap. The influences of the key process parameters on formation of the nanostructures were also investigated. It has been demonstrated that the morphology and dimension of the nanostructures were mainly controlled by working temperature and working pressure. One-dimensional nanostructures were fabricated at a lower working temperature whereas nanospheres were formed at a higher working temperature. Larger nanospheres could be obtained when a higher working pressure was applied. The XRD FTIR and NMR analyses evidenced that the nanostructures mainly consisted of d-phase Gaq3. Their DSC trace revealed two small exothermic peaks in addition to the melting endotherm. The one in lower temperature region was ascribed to a transition from d to b phase while another in higher temperature region could be identified as a transition from b to d phase. All the crystalline nanostructures show similar PL spectra due to absence of quantum confinement effect. They also exhibited a spectral blue shift because of a looser interligand spacing and reduced orbital overlap in their d-phase molecular structures. Y.-W. Yu T.-P. Perng Department of Materials Science and Engineering National Tsing Hua University Hsinchu 30013 Taiwan C.-P. Cho Department of Applied Materials and Optoelectronic Engineering National Chi Nan University Nantou 54561 Taiwan e-mail emily.cho31@msa.hinet.net T.-P. Perng H Department of Chemical Engineering and Materials Science Yuan Ze University Chung-Li 32003 Taiwan e-mail tpperng@mx.nthu.edu.tw Keywords Gaq3 1-D nanostructures Nanospheres .