TiO_2(Sm)の構造と結晶場 : けい光スペクトルに与える生成条件と摩砕の効果

概要

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The purpose of this work is to get some information on the correlation between the change in crystal structure of atomic long-range order and that in crystal field of short-range order during mechanochemical processes. The x-ray diffraction patterns and the fine structures of fluorescence spectra from doped Sm ions were observed on several TiO_2 crystals which were prepared by various procedures. TiO_2(Sm) of anatase type changed to that of rutile type by grinding. The fine structure of spectrum changed from anatase to rutile almost in parallel to the corresponding change in x-ray pattern. It shows that no essential difference exists between the long-range reordering and the short-range reordering during the mechanochemical phase change. The broadening of fine structures of spectra, however, was observed in neither well ground TiO_2(Sm) nor amorphous TiO_2 fired at temperatures lower than the crystallization temperature. Such amorphous phase of TiO_2 is considered to have a definite crystal field due to the ionic surrounding having the short-range order. This seems quite different from usual inorganic glasses, which give fluorescence spectra with broad structures from doped Sm ions.
社団法人日本材料学会の論文
1974-07-15