BaCO_3-M_2O_3混合粉末(M : La, Nd, Sm, Gd, Ho, Y)から反応焼結により合成したBaM_20_4の秩序無秩序転移

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rights: 社団法人日本セラミックス協会rights: 本文データは学協会の許諾に基づきCiNiiから複製したものであるrelation: IsVersionOf: http://ci.nii.ac.jp/naid/110002290617/Sintered bodies of BaM_2O_4 (M : La, Nd, Sm, Gd, Ho or Y) with CaFe_2O_4 related structure were synthesized by sintering BaCO_3 M_2O_3 mixtures. The temperature de pendence of oxygen ionic conductivity and the relation ship between the ionic radius of M^<3+> ions in B sites and the crystal structure of BaM_2O_4 were investigated. The ionic conductivity type in BaM_2O_4 was divided into two groups; (a) BaLa_2O_4, BaNd_2O_4 and BaSm_2O_4 with ord er disorder transition and (b) BaGd_2O_4, BaHO_2O_4 and BaY_2O_4 without the transition. There were vacant spaces in the crystal structure of BaNd_2O_4 and BaSm_2O_4 with order disorder transition due to the dis tortion in the a axis direction of an oxygen octahedron. By assuming that the vacant space is an oxygen vacan cy, the ionic conductivity in BaLa_2O_4, BaNd_2O_4 and BaSln_2O_4 has been explained with a model of the order disorder transition for oxygen vacancies without sig nificant shifting of cations in the crystal lattice.
社団法人日本セラミックス協会の論文
1994-06-01