Overall and local distortion effects on the metal{endash}nonmetal transitions of mixed valent perovskite type manganese oxides

Journal Article · Mon Sep 01 00:00:00 EDT 1997 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.366257· OSTI ID:542166

Kwon, Y; Chi, E; Kang, J ^[1]; Hur, N H ^[2]

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1. Department of Chemistry, Sung Kyun Kwan University, Suwon, 440-746 (Korea)
2. Korea Research Institute of Standards and Science, Taejon, 305-600 (Korea)

The metal{endash}nonmetal (MN) transition data of mixed valent manganese oxide perovskites A{sub 1{minus}x}A{sub x}{sup {prime}}MnO{sub 3} (A: trivalent lanthanide metals, A{sup {prime}}: divalent metals, 0.2{lt}x{lt}0.5) are analyzed in terms of the tolerance factor (t), and the standard deviation ({sigma}) of the A-site cation sizes. The interplay of these two parameters that measure the overall and atomic scale distortions, respectively, determine whether a compound can show a MN transition or not and its transition temperature (T{sub MN}). In order to show a MN transition, a compound should have t{gt}0.906 and {sigma}{approx_lt}{sigma}=232t{minus}202 (pm). Large t and small {sigma} are favorable for high T{sub MN}. T{sub MN} data of A{sub 0.7}Ba{sub 0.15}Sr{sub 0.15}MnO{sub 3} (A=La, Pr, Nd, Sm), A{sub 0.7}Ba{sub 0.15}Ca{sub 0.15}MnO{sub 3} (A=La, Pr, Nd, Sm), (La{sub 0.7}Ca{sub 0.3}){sub x}(Gd{sub 0.7}Ba{sub 0.3}){sub 1{minus}x}MnO{sub 3} (x=0.1, 0.3, 0.5, 0.7, 0.9), and (Nd{sub 0.7}Ca{sub 0.3}){sub x} (Gd{sub 0.7}Ba{sub 0.3}){sub 1{minus}x}MnO{sub 3} (x=0.25, 0.3, 0.5, 0.55, 0.7, 0.75) newly synthesized are reported. {copyright} {ital 1997 American Institute of Physics.}

• OSTI ID: 542166
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 6 Vol. 82; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM COMPOUNDS
BARIUM OXIDES
BOND ANGLE
CALCIUM COMPOUNDS
CALCIUM OXIDES
CRYSTAL STRUCTURE
ELECTRIC CONDUCTIVITY
GADOLINIUM COMPOUNDS
GADOLINIUM OXIDES
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
LATTICE PARAMETERS
MANGANESE OXIDES
NEODYMIUM COMPOUNDS
NIOBIUM OXIDES
PEROVSKITES
PRASEODYMIUM COMPOUNDS
PRASEODYMIUM OXIDES
SAMARIUM COMPOUNDS
SAMARIUM OXIDES
STOICHIOMETRY
STRONTIUM COMPOUNDS
X-RAY DIFFRACTION