Local symmetry lowering in CdMn{sub 2}O{sub 4} spinel

Journal Article · Sun Dec 14 04:00:00 EST 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4903949· OSTI ID:22402776

Oliveira, G. N. P.; Lopes, A. M. L., ^[1]; Teixeira, R.; Silva, M. R. ^[1]; Mendonça, T. M.; Correia, J. G. ^[2]

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1. CFNUL - Centro de Física Nuclear, Universidade de Lisboa, Av. Prof. Gama Pinto 2, 1649-003 Lisboa (Portugal)
2. C2TN, Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, 2695-066 Bobadela LRS (Portugal)

This work presents an atomic scale study of the electric field gradient (EFG) in the tetragonally distorted CdMn{sub 2}O{sub 4} spinel manganite. The EFG temperature dependence at the Cd and Mn sites was followed via perturbed angular correlation measurements with the {sup 111}In and {sup 111m}Cd probes, from 873 down to 12 K at Isolde-CERN. The results show that in the 12–600 K temperature range, a single Jahn-Teller distorted local phase exists. However above 100 K, a dynamic lattice distortion, evidenced by time dependent EFG fluctuations, sets in suggesting a structural instability. Above 600 K, a local MnO{sub 6} octahedra with relaxed Jahn-Teller distortions emerge and grow in the low temperature matrix, although no macroscopic tetragonal to cubic phase transition was observed.

• OSTI ID: 22402776
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 22 Vol. 116; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CADMIUM 111
CERN
ELECTRIC FIELDS
FLUCTUATIONS
INDIUM 111
INSTABILITY
JAHN-TELLER EFFECT
MANGANESE OXIDES
PERTURBED ANGULAR CORRELATION
PHASE TRANSFORMATIONS
PROBES
SPINELS
SYMMETRY
TEMPERATURE DEPENDENCE
TIME DEPENDENCE