Growth and characterization of Ca₂₋<i>_xAe_x</i>Al₂SiO₇ (<i>Ae</i> = Sr, Ba) piezoelectric single crystals

Abstract

We report the effects of Sr or Ba substitution on the crystal growth and electrical and mechanical properties of Ca 2 Al 2 SiO 7 (CAS) piezoelectric single crystals, which are suitable for use in high-temperature pressure sensors. Ba was scarcely incorporated in the crystal lattice of CAS. Strontium-substituted CAS single crystal with a nominal chemical composition Ca 0.75 Sr 1.25 Al 2 SiO 7 (CSAS125) was grown by the Czochralski method. Although the piezoelectric modulus d¤ 31 of CSAS125 is a bit lower than that of the CAS crystal, the rupture strength of the (XYt)45°rotation cut substrate of CSAS125 crystal was 170 MPa, which was 1.2 times higher than that of CAS crystal. By considering the rupture strength and the apparent piezoelectric d à 31 coefficient calculated for the crystal rotation cut of CAS crystal, the CSAS125 crystal substrate with a rotation cut of (XYt)25°was found to indicate a rupture strength of 220 MPa and a piezoelectric d¤ 31 coefficient of approximately 2 pC/N.

Fabrication and Application of Single Crystal Fiber: Review and Prospective

“…High temperature piezoelectric materials are also in high demand with potential application in gas sensors, gas injectors, and combustion pressure sensors. [ 199 ] Oshima et al. prepared chemical compositions Ca 2− x Sr x Al 2 SiO 7 (CSAS100 x ) with x = 0.50, 1.00, 1.25, 1.50, 1.75, 2.00, and Ca 2− x Ba x Al 2 SiO 7 (CBAS100 x ) with x = 0.01, 0.05 and grew them into single crystal by LHPG method.…”

Leakage electric field in longitudinal vibration from piezoelectric bars

“…Piezoelectric materials are widely used in various devices, such as transducers and sensors. [1][2][3][4][5][6][7] Currently, langasitefamily, 3,4,6,[8][9][10] melilite-family, [11][12][13][14] and RCOB-family (R = rare-earth elements) [15][16][17][18][19][20] piezoelectric single crystals are attracting considerable attention because their hightemperature piezoelectric properties can be exploited for various applications in automobile engines and turbines, for example, pressure sensors operating in high-temperature environments. Such piezoelectric single crystals have low dielectric permittivity.…”

Electroacoustical constants and Rayleigh surface acoustic wave propagation characteristics of calcium aluminate silicate Ca2Al2SiO7 single crystals

“…22,23) Then, a new biosensor device using the CAS crystal should be expected because both CAS and Sr-substituted CAS crystals can be grown by the Cz technique. 24,25) Moreover, since the CAS crystal exhibits both high resistivity and stable piezoelectric properties even at higher temperatures, 7) the crystal has a potential for SAW sensor applications at high temperatures mentioned above. Therefore, it is important to investigate the SAW properties of melilite-type crystals.…”