Đang chuẩn bị liên kết để tải về tài liệu:
Báo cáo hóa học: " Enhancement of Sm3+ emission by SnO2 nanocrystals in the silica matrix"

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: Enhancement of Sm3+ emission by SnO2 nanocrystals in the silica matrix | Nanoscale Res Lett 2007 2 100-103 DOI 10.1007 S11671-006-9037-1 NANO EXPRESS Enhancement of Sm3 emission by SnO2 nanocrystals in the silica matrix Jin Mu Lingyun Liu Shi-Zhao Kang Published online 17 January 2007 To the authors 2007 Abstract Silica xerogels containing Sm3 ions and SnO2 nanocrystals were prepared in a sol-gel process. The image of transmission electron microscopy TEM shows that the SnO2 nanocrystals are dispersed in the silica matrix. The X-ray diffraction XRD of the sample confirms the tetragonal phase of SnO2. The xerogels containing SnO2 nanocrystals and Sm3 ions display the characteristic emission of Sm3 ions 4G5 2 fi 6H7 J 5 2 7 2 9 2 at the excitation of 335 nm which energy corresponds to the energy gap of the SnO2 nanocrystals while no emission of Sm3 ions can be observed for the samples containing Sm3 ions. The enhancement of the Sm3 emission is probably due to the energy transfer from SnO2 nanocrystals to Sm3 ions. Keywords Sm3 ions Emission Sensibilization SnO2 nanocrystals Silica matrix Introduction Sm3 ions can exhibit strong emission in the orange spectral region. The silica gel has been known as an excellent host material for rare earth ions because of its high transparency compositional variety and easy mass production 1 . Therefore the silica gel containing Sm3 ions has a potential application for high-density J. Mu H L. Liu S.-Z. Kang Department of Chemistry Key Laboratory for Ultrafine Materials of Ministry of Education East China University of Science and Technology 130 Meilong Road Shanghai 200237 China e-mail jinmu@ecust.edu.cn optical memory 2 3 . However the Sm3 -doped gel cannot emit strong fluorescence 4 . It is necessary to introduce a sensitizer into the gel containing Sm3 ions in order to obtain strong emission of Sm3 ions. Our previous study 5 showed that there existed the interaction between Eu3 ions and CdS nanoparticles in the silica matrix. Furthermore Franzo et al. 6 Brovelli et al. 7 Bang et al. 8 and Selvan et al.