Bi-Ba-Cu-O系ガラスの結晶化挙動

概要

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Crystallization behavior of Bi-Ba-Cu-O glasses has been studied. Glass-transition temperature T_g and crystallization onset temperature T_x are slightly lower than those of Bi-Sr-Ca-Cu-O glasses. (T_x-T_g) 's of the present glasses are, however, similar to those of Bi-Sr-Ca-Cu-O glasses. The temperatures of the first endothermic peaks in the DSC curves T_<Endo> are about 700℃ when BiO_<1.5>/BaO>1 and about 850℃ when BiO_<1.5>/Bao<1, which are assined to the melting of CuBi_2O_4 and BaCuO_2 crystals formed in the products, respectively. BaBiO_<2.55> or BaBiO_<2.77> crystal is formed in the first stage of crystallization and transformed to BaBiO_3 crystal at higher temperatures. No crystal containing all the cation species of Bi, Ba and Cu is formed from the present glasses, which can be attrituted to th extremely high stability of BaBiO_<3-χ> crystal. The activation energies for crystallization E_a's are 382 and 325kJ/mol for the first and second peaks which are assined to the formation of BaBiO_<2.77> crystal in the DSC curve for 50BiO_<1.5>・25BaO・25CuO glass. It has been found that E_a's for Bi-Ca-Cu-O and Bi-Sr-Cu-O glasses are higher than those of Bi-Sr-Ca-Cu-O glasses.
社団法人日本材料学会の論文
1993-05-15