Substitution behavior of x(Na{sub 0.5}K{sub 0.5})NbO{sub 3}-(1 − x)BaTiO{sub 3} ceramics for multilayer ceramic capacitors by a near edge x-ray absorption fine structure analysis

Journal Article · Mon Jun 30 04:00:00 EDT 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4886579· OSTI ID:22303900

Ha, Jooyeon; Ryu, Jiseung; Lee, Heesoo ^[1]

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1. School of Materials Science and Engineering, Pusan National University, Busan 609-735 (Korea, Republic of)

The doping effect of (Na{sub 0.5}K{sub 0.5})NbO{sub 3} (NKN) as alternatives for rare-earth elements on the electrical properties of BaTiO{sub 3} has been investigated, in terms of their substitution behavior. The dielectric constant of a specimen with x = 0.05 was about 79% higher than that of pure BaTiO{sub 3}, and the temperature coefficient of capacitance was satisfied by the X7R specification. The specimen with x = 0.05 showed the lowest tetragonality among the four compositions and had a fine grain size of <2 μm. Although the addition of NKN decreased the specimen's tetragonality, the electrical properties were enhanced by the formation of defect dipoles and conduction electrons, which resulted from an acceptor and donor substitution behavior. Through O K-edge near edge x-ray absorption fine structure spectroscopy, the practical substitution behavior was defined by the change in Ti 3d orbital states. The energy separation of the Ti 3d orbitals was more apparent with the specimen of x = 0.05, which is related to the donor level from the donor substitution of Nb{sup 5+} ion for Ti-sites. Therefore, the simultaneous substitution of Na{sup +}/K{sup +} and Nb{sup 5+} ions into BaTiO{sub 3} can improve dielectric properties, based on the charge-transfer process.

• OSTI ID: 22303900
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 26 Vol. 104; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION
ABSORPTION SPECTROSCOPY
BARIUM COMPOUNDS
CAPACITORS
CERAMICS
CRYSTAL DEFECTS
DIPOLES
FINE STRUCTURE
GRAIN SIZE
LAYERS
NIOBATES
PERMITTIVITY
POTASSIUM COMPOUNDS
RARE EARTHS
SODIUM COMPOUNDS
TEMPERATURE COEFFICIENT
TITANATES
X RADIATION
X-RAY SPECTROSCOPY