tailieunhanh - Báo cáo hóa học: " Tapered ZnO Whiskers: {hkil}-Specific Mosaic Twinning VLS Growth from a Partially Molten Bottom Source"

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: Tapered ZnO Whiskers: {hkil}-Specific Mosaic Twinning VLS Growth from a Partially Molten Bottom Source | Nanoscale Res Lett 2009 4 503-512 DOI S11671-009-9273-2 NANO EXPRESS Tapered ZnO Whiskers hki7 -Specific Mosaic Twinning VLS Growth from a Partially Molten Bottom Source Bang-Hao Huang Pouyan Shen Shuei-Yuan Chen Received 14 December 2008 Accepted 6 February 2009 Published online 25 February 2009 to the authors 2009 Abstract Zn particulates overlaid with wurtzite W -type ZnO condensates having nearly orthogonal 1011g and 1121 facets were found to self-catalyze unusual tapered W-ZnO whiskers upon isothermal atmospheric annealing . thermal oxidation at 600 C. Analytical electron microscopic observations indicated that such whiskers formed tapered slabs having mosaic 1011 and 2ĨĨ1 twinned domains. The tapered whiskers can be rationalized by an alternative vapor-liquid-solid growth . hkil -specific coalescence twinning growth from the ZnO condensates taking advantage of a partially molten bottom source of Zn and the adsorption of atoms at the whisker tips and ledges under the influence of capillarity effect. The tapered whiskers having strong photoluminescence at 391 nm and with a considerable flexibility could have potential applications. Keywords ZnO Whiskers Pulsed laser ablation VLS Photoluminescence Introduction The motivation of this research was to prove experimentally that tapered whiskers bounded by specific crystal surfaces can be formed by an unusual vapor-liquid-solid . Huang P. Shen Department of Materials and Optoelectronic Science Institute of Materials Science and Engineering National Sun Yat-sen University Kaohsiung Taiwan ROC . Chen H Department of Mechanical and Automation Engineering I-Shou University Kaohsiung Taiwan ROC e-mail steven@ VLS growth mechanism . hkil -specific coalescence twinning growth from crystalline condensates taking advantage of a partially molten bottom source rather than a small liquid globular at the tip of the whisker. The VLS mechanism of single crystal growth 1 was generally accepted to .