Characteristics and optical spectra of V : YAG crystal grown in reducing atmosphere
Data(s) |
2006
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Resumo |
A V:YAG single crystal was grown by the temperature gradient technique (TGT) with graphite-heating elements. The as-grown crystal has different colorations of light green and yellow brown in different parts. Distribution of vanadium in three samples with different colorations was determined by inductively coupled plasma-mass spectrometry. From the absorption spectrum of the yellow-brown part with peaks at 370, 820 and 1320nm, we can deduce that the reducing atmosphere of carbon diffused from the heating elements can increase the concentration of tetrahedral V3+ ions and induce F color centers. All three samples exhibited light-green color after annealing in vacuum or H-2 atmospheres. In the vacuum annealing process, the V3+ ions in tetrahedral positions were enhanced through two methods: one method is the exchanging of octahedral V3+ and tetrahedral Al3+ ions in neighboring sites under thermal excitation, the other is that F color centers were thoroughly eliminated and the escaped free electrons could be captured by V ions with higher valance states to further improve the concentration of tetrahedral V3+ ions. Besides the two mechanisms, the H-2 annealing process greatly improved the V-tetra(3+) ions through the reduction effect of H-2. (c) 2006 Elsevier B.V. All rights reserved. |
Identificador | |
Idioma(s) |
英语 |
Fonte |
Zhang Dan;苏良碧;李红军;Qian Xiaobo;徐军.,J. Cryst. Growth,2006,294(2):437-441 |
Palavras-Chave | #光学材料;晶体 #absorption spectra #reducing atmosphere #as-grown crystal #graphite-heating elements |
Tipo |
期刊论文 |