Polar nanoregions and dielectric properties in high-strain lead-free 0.93(Bi{sub 1/2}Na{sub 1/2})TiO{sub 3}-0.07BaTiO{sub 3} piezoelectric single crystals

Journal Article · Tue Jan 07 00:00:00 EST 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4861030· OSTI ID:22271294

Chen, Cheng-Sao ^[1]; Chen, Pin-Yi ^[2]; Tu, Chi-Shun ^[3]

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1. Department of Mechanical Engineering, Hwa-Hsia Institute of Technology, New Taipei City 23567, Taiwan (China)
2. Department of Mechanical Engineering, Ming-Chi University of Technology, New Taipei City 24301, Taiwan (China)
3. Graduate Institute of Applied Science and Engineering, Fu Jen Catholic University, New Taipei City 24205, Taiwan (China)

A structural coexistence of rhombohedral (R) and tetragonal (T) phases has been revealed in the (001){sub c}-cut lead-free 0.93(Bi{sub 1/2}Na{sub 1/2})TiO{sub 3}–0.07BaTiO{sub 3} (BNB7T) piezoelectric crystals, which grown by the self-flux method, in the lower temperatures by high-resolution synchrotron X-ray diffraction, reciprocal space mapping, and transmission electron microscopy. The dielectric permittivity exhibits a thermal hysteresis in the region of 120–260 °C, implying a first-order-like phase transition from R+T to T. The real part (ε′) of dielectric permittivity begins to deviates from the Curie-Weiss equation, ε′ = C/(T − T{sub o}), from the Burns temperature T{sub B} = 460 °C, below which the polar nanoregions (or nanoclusters) develop and attenuate dielectric responses. The polar nanoregions of 5–10 nm were revealed by high-resolution transmission electron microscope. The normal piezoelectric coefficient d{sub 33} exhibits a rapid increase at E = 15–20 kV/cm and reaches a maximum of d{sub 33} ∼450 pC/N. The high piezoelectric response and E-field induced strain in BNB7T single crystals can be attributed to structural phase transitions under an E-field application.

• OSTI ID: 22271294
• Journal Information: Journal of Applied Physics, Vol. 115, Issue 1; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
77 NANOSCIENCE AND NANOTECHNOLOGY
BARIUM COMPOUNDS
BISMUTH COMPOUNDS
DIELECTRIC MATERIALS
MONOCRYSTALS
NANOSTRUCTURES
PERMITTIVITY
PHASE TRANSFORMATIONS
PIEZOELECTRICITY
SODIUM COMPOUNDS
STRAINS
TEMPERATURE DEPENDENCE
TITANIUM OXIDES
TRANSMISSION ELECTRON MICROSCOPY
TRIGONAL LATTICES
X-RAY DIFFRACTION