Crystal Structure and Metal-Insulator Transition of La 1- x Sr x CoO 3

Authors: Mineshige A.¹; Inaba M.¹; Yao T.¹; Ogumi Z.¹; Kikuchi K.²; Kawase M.³

Source: Journal of Solid State Chemistry, Volume 121, Number 2, February 1996 , pp. 423-429(7)

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Abstract:

Crystal structure of perovskite La 1 - x Sr x CoO 3 (0.0 < x < 0.7) was precisely determined by powder X-ray Rietveld analysis, and its correlation with the electrical properties was discussed. The space group was assigned to rhombohedral R 3 c in the range 0.0 < x < 0.5 and to cubic Pm 3 m in the range 0.55 < x < 0.7. At x =~ 0.25 the Co-O distance and Co-O-Co angle of this system showed an abrupt decrease and increase with increasing x , respectively, and the conductivity behavior changed from semiconducting to metallic. The abrupt changes in crystal structure were attributed to a change in the band structure at the transition from semiconducting to metallic, that is, an increase in the overlap between the valence band and doped hole sates.

Language: English

Document Type: Research article

Affiliations: 1: Graduate School of Engineering, Kyoto University, Sakyo-ku, Kyoto 606-01, Japan 2: Department of Materials Science, University of Shiga Prefecture, Hikone, Shiga, 522, Japan 3: Faculty of Education, Kagawa University, Takamatsu, Kagawa, 760, Japan

Publication date: 1996-02-01