Chemical and structural effects on the high-temperature mechanical behavior of (1−x)(Na{sub 1/2}Bi{sub 1/2})TiO{sub 3}-xBaTiO{sub 3} ceramics

Journal Article · Tue Apr 07 00:00:00 EDT 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4916784· OSTI ID:22399391

Deluca, Marco ^[1]; Picht, Gunnar ^[2]; Hoffmann, Michael J. ^[2]; Rechtenbach, Annett; Töpfer, Jörg ^[3]; Schader, Florian H.

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1. Materials Center Leoben Forschung GmbH, Roseggerstraße 12, 8700 Leoben (Austria)
2. Institute of Applied Materials, Ceramics in Mechanical Engineering, Karlsruhe Institute of Technology, 76131 Karlsruhe (Germany)
3. Department of SciTec, University of Applied Sciences Jena, Carl-Zeiß-Promenade 2, 07745 Jena (Germany)

Bismuth sodium titanate–barium titanate [(1−x)(Na{sub 1/2}Bi{sub 1/2})TiO{sub 3}-xBaTiO{sub 3}, NBT-100xBT] is one of the most well studied lead-free piezoelectric materials due in large part to the high field-induced strain attainable in compositions near the morphotropic phase boundary (x = 0.06). The BaTiO{sub 3}-rich side of the phase diagram, however, has not yet been as comprehensively studied, although it might be important for piezoelectric and positive temperature coefficient ceramic applications. In this work, we present a thorough study of BaTiO{sub 3}-rich NBT-100xBT by ferroelastic measurements, dielectric permittivity, X-ray diffraction, and Raman spectroscopy. We show that the high-temperature mechanical behavior, i.e., above the Curie temperature, T{sub C}, is influenced by local disorder, which appears also in pure BT. On the other hand, in NBT-100xBT (x < 1.0), lattice distortion, i.e., tetragonality, increases, and this impacts both the mechanical and dielectric properties. This increase in lattice distortion upon chemical substitution is counterintuitive by merely reasoning on the ionic size, and is due to the change in the A-O bond character induced by the Bi{sup 3+} electron lone pair, as indicated by Raman spectroscopy.

• OSTI ID: 22399391
• Journal Information: Journal of Applied Physics, Vol. 117, Issue 13; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BISMUTH COMPOUNDS
BISMUTH IONS
CERAMICS
CONCENTRATION RATIO
CURIE POINT
DIELECTRIC MATERIALS
ELECTRONS
PERMITTIVITY
PHASE DIAGRAMS
PIEZOELECTRICITY
RAMAN SPECTROSCOPY
SODIUM COMPOUNDS
STRAINS
TEMPERATURE COEFFICIENT
TEMPERATURE DEPENDENCE
TITANATES
TITANIUM OXIDES
X-RAY DIFFRACTION