New high permittivity tetragonal tungsten bronze dielectrics Ba{sub 2}LaMNb{sub 4}O{sub 15}: M=Mn, Fe
- Department of Engineering Materials, University of Sheffield, Mappin Street, Sheffield, S1 3JD (United Kingdom)
The new phases Ba{sub 2}LaMNb{sub 4}O{sub 15}: M=Mn, Fe were prepared by solid state reaction at 1100 deg. C. They have the tetragonal tungsten bronze structure, space group P4/mbm, at room temperature. The two octahedral sites show partial order of M and Nb with preferential occupancy of the smaller B(1) sites by M. Both phases have high permittivities 90+-15 over the range 10-320 K. Ba{sub 2}LaFeNb{sub 4}O{sub 15} is highly insulating with bulk conductivity <<10{sup -8} ohm{sup -1} cm{sup -1} at 25 deg. C and tan delta<<0.001 over the range 100-320 K and at 10{sup 5} Hz. Solid solutions between these new phases and the compositionally and structurally related relaxor ferroelectric Ba{sub 2}LaTi{sub 2}Nb{sub 3}O{sub 15} show gradual loss of ferroelectric behaviour attributed to replacement of polarisable Ti{sup 4+} by a mixture of (Mn, Fe){sup 3+} and Nb{sup 5+}. - Graphical Abstract: Tetragonal tungsten bronze structure of Ba{sub 2}La(Mn, Fe)Nb{sub 4}O{sub 15} from two different viewpoints.
- OSTI ID:
- 21372530
- Journal Information:
- Journal of Solid State Chemistry, Vol. 183, Issue 3; Other Information: DOI: 10.1016/j.jssc.2009.11.032; PII: S0022-4596(09)00561-1; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
Similar Records
Manipulation of polar order in the “empty” tetragonal tungsten bronzes: Ba{sub 4-x}Sr{sub x}Dy{sub 0.67}□{sub 1.33}Nb{sub 10}O{sub 30}, x = 0, 0.25, 0.5, 1, 2, 3
Structural and relaxor-like dielectric properties of unfilled tungsten bronzes Ba{sub 5−5x}Sm{sub 5x}Ti{sub 5x}Nb{sub 10−5x}O{sub 30}
Related Subjects
BARIUM COMPOUNDS
FERROELECTRIC MATERIALS
IRON COMPOUNDS
LANTHANUM COMPOUNDS
MANGANESE COMPOUNDS
NIOBIUM COMPOUNDS
NIOBIUM IONS
OXIDES
PERMITTIVITY
TEMPERATURE RANGE 0000-0013 K
TEMPERATURE RANGE 0013-0065 K
TEMPERATURE RANGE 0065-0273 K
TEMPERATURE RANGE 0273-0400 K
TETRAGONAL LATTICES
TITANIUM IONS
TUNGSTEN BRONZE
ALKALINE EARTH METAL COMPOUNDS
ALLOYS
CHALCOGENIDES
CHARGED PARTICLES
COPPER ALLOYS
COPPER BASE ALLOYS
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DIELECTRIC MATERIALS
DIELECTRIC PROPERTIES
ELECTRICAL PROPERTIES
IONS
MATERIALS
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
REFRACTORY METAL COMPOUNDS
TEMPERATURE RANGE
TRANSITION ELEMENT ALLOYS
TRANSITION ELEMENT COMPOUNDS
TUNGSTEN ALLOYS