The effect of the addition of Bi-perovskites to (Li 0.04 K 0.52 Na 0.44 )(Nb 0.84 Ta 0.1 Sb 0.06 )O 3 (LF4) ceramics was studied to improve the properties of lead-free piezoelectrics. Ceramics with the relative density above 96% were successfully obtained by a solid state reaction process. The changes in lattice parameters indicated that the vacancy concentration at the A-site of the perovskite structure and the tetragonality of the crystal lattice were reduced with the addition of BiFeO 3 . The addition of BiFeO 3 changed the LF4 to a soft-piezoelectric.··The electrical insulation of the LF4 was improved with the addition of BiFeO 3 , which made a full poling possible under high electric fields. A few mol% of BiFeO 3 was effective to improve the remanent polarization of the LF4 ceramics and a piezoelectric d 33 constant of about 358 pm/V was obtained in the 0.4 mol% doped ceramics.

10.1109/isaf.2007.4393358

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Citations (1)

Domain Wall Engineering in Potassium Niobate Single Crystals and Their Piezoelectric Properties

Key engineering materials (2006)

Keisuke Yokoh Song Min Nam Hirofumi Kakemoto Takaaki Tsurumi Hirohiko Kumagai

Potassium niobate

10.4028/0-87849-411-1.147

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Structural Characterization of K₃Li₂Nb₅O₁₅Single Crystals by Combining High-Resolution X-Ray Diffractometry and Topography

Japanese Journal of Applied Physics (2002)

Kazuyuki Kaigawa Katsuhiro Imai Akihiko Honda Minoru Imaeda Hiroaki Sakai

High-resolution multiple-crystal multiple-reflection X-ray diffractometry is used for the structural characterization of nonlinear optical single crystals of K3Li2Nb5O15 (KLN) grown by the micro-pulling-down (µ-PD) method. The combination of high-resolution X-ray diffractometry and topography shows that the lattice parameters along the c-axis (c-parameters) decrease towards the seed crystals, because of the decrease in the K content and increase in the Nb content. However, the KLN single crystals exhibit multi domain structures in which discontinuous changes in the c-parameters are periodically observed along the growth direction, despite the compositional change being continuous. Large mosaic structures due to discontinuous tilt in the lattice planes are also observed at the boundaries between the domains.

Characterization

Lattice (music)

Reflection

Lattice constant

10.1143/jjap.41.5594

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Citations (1)

Introduction of fine engineered domain configurations into potassium niobate single crystal and their piezoelectric properties

Preprints of Annual Meeting of The Ceramic Society of Japan Preprints of Fall Meeting of The Ceramic Society of Japan Preprints of Annual Meeting of The Ceramic Society of Japan, 2004 (2004)

K. Muraoka Hirofumi Kakemoto Satoshi Wada Takaaki Tsurumi Hirohiko Kumagai

Potassium niobate

10.14853/pcersj.2004s.0.10.0

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Introduction of Fine Engineered Domain Configuration into Potassium Niobate Single Crystals

Key engineering materials (2007)

Keisuke Yokoh Tomomitsu Muraishi Song Min Nam Hirofumi Kakemoto Takaaki Tsurumi

Potassium niobate

10.4028/0-87849-449-9.89

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Local Structure Analysis of Bi₂WO₆ (Special Issue : Ferroelectric Materials and Their Applications)

Japanese Journal of Applied Physics (2012)

Yasuhiro Yoneda Shinji Kohara Hiroaki Takeda Takaaki Tsurumi

Source

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Growth and characterization of strontium-substituted Ca2Al2SiO7 piezoelectric single crystals

Journal of the Ceramic Society of Japan (2016)

Hiroaki Takeda Kyohei Yoshida Hiroki Okudera Kheirreddine Lebbou Takuya Hoshina

We report the effect of Sr substitution on the structural, electrical, and mechanical properties of Ca2Al2SiO7 (CAS) piezoelectric single crystals for high-temperature pressure sensors. Single crystals of Sr-substituted CAS (Sr-CAS) with a nominal chemical composition of CaSrAl2SiO7 were grown by using the Czochralski technique. The single-crystal X-ray structure analysis revealed that Sr atoms were placed in the Ca decahedral sites, which decreased the polyhedral distortion slightly. The piezoelectric modulus d′31 and electrical resistivity of Sr-CAS measured at 23°C were slightly lower than those of CAS, but still sufficient for the satisfactory performance of the produced sensors. The rupture strength of the Sr-CAS crystal was 230 MPa, 1.2 times higher than that of a CAS crystal. The obtained results suggest that Sr-CAS crystals can be candidate materials for high-temperature pressure sensors.

Crystal (programming language)

10.2109/jcersj2.16206

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Crystl growth of Bismuth layer-structured ferroelectrics BaBi4Ti4O15 single crystal produced by bridgman method and their piezoelectric properties

Preprints of Annual Meeting of The Ceramic Society of Japan Preprints of Fall Meeting of The Ceramic Society of Japan Preprints of Annual Meeting of The Ceramic Society of Japan, 2004 (2004)

Hiroshi Sawase Song‐Min Nam Hirofumi Kakemoto Satoshi Wada Takaaki Tsurumi

Bismuth

10.14853/pcersj.2004s.0.44.0

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Enhanced Piezoelectric Property of Barium Titanate Single Crystals by Domain Wall Engineering Using Patterning Electrode

Ferroelectrics (2006)

Satoshi Wada Koichi Yako Tomomitsu Muraishi Keisuke Yokoh Song‐Min Nam

Abstract For the [111] oriented barium titanate (BaTiO3) single crystals, the patterning electrode was used to induce the finer engineered domain configurations with domain size below 5 μ m. The poling treatment was performed at 134.0°C under electric fields below 6 kV/cm to inhibit the burning of the patterning electrode with photoresist. As the results, the gradient domain sizes from 3 μm (high voltage side) to 8–9 μ m (ground side) were induced into the 31 resonator along thickness direction. For this resonator, the d31 was measured at −243.2 pC/N using a resonance-antiresonance method. Keywords: Barium titanatedomain engineeringdomain wall Acknowledgments We would like to thank Mr. O. Nakao of Fujikura Ltd. for preparing the TSSG-grown BaTiO3 single crystals with excellent chemical quality. This study was partially supported by (1) a Grant-in-Aid for Scientific Research (16656201) from the Ministry of Education, Culture, Sports, Science, and Technology, Japan, (2) the Japan Securities Scholarship Foundation, (3) the Toray Science Foundation, (4) the Kurata Memorial Hitachi Science and Technology Foundation, (5) the Electro-Mechanic Technology Advanced Foundation, (6) the Tokuyama Science Foundation and (7) the Yazaki Memorial Foundation for Science and Technology.

Barium titanate

Foundation (evidence)

Poling

10.1080/00150190600888652

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Citations (19)

Doping effect of Nb on ionic polarization of SrTiO3

Journal of the Ceramic Society of Japan (2019)

Junji Nishiyama Kazuki Kanehara Hiroaki Takeda Takaaki Tsurumi Takuya Hoshina

THz dielectric spectra of Nb-doped SrTiO3 single crystals were measured using the far-infrared spectroscopic ellipsometer to understand the doping effect of Nb on ionic polarization. The frequency of the Slater transverse optical (TO) mode increased with the doping amount of Nb, meaning the decrease in the ionic polarization by Nb doping. From the change in the Slater TO mode frequency, it was estimated that the ionic polarizability of 1% Nb-doped SrTiO3 was 10.4% lower than that of undoped SrTiO3. This result suggested that the intrinsic permittivity of Nb-doped SrTiO3 is lower than that of that of undoped SrTiO3. First principles calculations revealed that the Nb 4d-orbitals contributes to the covalency between B-site cations and O ions, however, the covalency is suppressed due to the electron carrier doping. The doped electrons causes the decrease in the long-range Coulomb force and the increase in short-range elastic force, and therefore the ionic polarizability is decreased by Nb doping.

Ellipsometry

10.2109/jcersj2.19031

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Citations (10)