Polar fluctuations in Mn substituted KTaO{sub 3} ceramics

Journal Article · Wed Sep 15 00:00:00 EDT 2010 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3481857· OSTI ID:21476468

Axelsson, Anna-Karin ^[1]; Yuya, Pan ^[2]; Valant, Matjaz ^[1]; Vilarinho, Paula M ^[3]; Alford, Neil McN ^[1]

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1. Department of Materials, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom)
2. London South Bank University, Borough Road, SE1 0AA London (United Kingdom)
3. University of Nova Gorica, Materials Research Laboratory, 5000 Nova Gorica (Slovenia)

Polar fluctuations were found in KTaO{sub 3} when K{sup +} was substituted with Mn{sup 2+} on the A-site. The temperature dependence of the real part of the dielectric permittivity of (K{sub 1-2x}Mn{sub x{open_square}x})TaO{sub 3} ceramics (x=0-0.05) shows a diffuse maximum between 50-100 K in the frequency range 10{sup 2}-10{sup 6} Hz, shifting to higher temperature with increasing frequency and Mn content. The results are analyzed using a modified Curie-Weiss law, the Cole-Cole equation and the Arrhenius law. Here it is suggested that the observed relaxor-type dielectric behavior is attributed to the formation of electric dipoles originating from two distinct sources; one from an atomic off-center position when Mn{sup 2+} substitutes for K{sup +} and one from the anion deficiencies formed by these aliovalent substitutions.

• OSTI ID: 21476468
• Journal Information: Journal of Applied Physics, Vol. 108, Issue 6; Other Information: DOI: 10.1063/1.3481857; (c) 2010 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANIONS
CERAMICS
CURIE-WEISS LAW
DIELECTRIC MATERIALS
ELECTRIC DIPOLES
FLUCTUATIONS
FREQUENCY DEPENDENCE
MANGANESE COMPOUNDS
MANGANESE IONS
PERMITTIVITY
POLARIZATION
POTASSIUM COMPOUNDS
POTASSIUM IONS
TANTALATES
TEMPERATURE DEPENDENCE
ALKALI METAL COMPOUNDS
CHARGED PARTICLES
DIELECTRIC PROPERTIES
DIPOLES
ELECTRICAL PROPERTIES
IONS
MATERIALS
MULTIPOLES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
REFRACTORY METAL COMPOUNDS
TANTALUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
VARIATIONS