The room temperature dielectric permittivity of  oriented 0.37BiScO3-0.63PbTiO3 (BSPT63) crystals with a morphotropic phase boundary (MPB) composition was found to be 1400, lower than that of BSPT57 crystals with rhombohedral phase (∼3000), but much higher than that of the tetragonal crystal BSPT66 (∼200). The Curie temperature of BSPT63 single crystals along  was found to be about 443°C, while the values were around 440°C and 445°C for  and  oriented crystals, respectively. Evidence of a ferroelectric-ferroelectric phase transformation temperature was associated with a dielectric anomaly occurring around 310-350°C for different orientations, indicating a strong curvature of the MPB. The coercive fields (Ec) were found to be 20kV/cm for  oriented crystals, 24kV/cm and 27kV/cm for  and  directions, respectively. The piezoelectric response for  oriented samples (d 33 = 900pC/N) is weaker than that in rhombohedral phase (d 33 = 1200pC/N) but much higher than that in tetragonal phase (d 33 =200 pC/N). The strain piezoelectric d33 improved with the temperature increasing owing to dielectric permittivity increment, while the voltage piezoelectric g33 is independent of temperature (g 33 ∼0.074 m2/C). Evidence of a monoclinic phase for BSPT63 crystals is inferred using the X-ray powder diffraction (XRD), and the lattice parameters were calculated to be a = 4.0751 Å, b = 3.9765 Å, c = 3.9893 Å and β= 90.166°.
|Original language||English (US)|
|Number of pages||5|
|Journal||Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers|
|Issue number||9 A|
|State||Published - Sep 1 2004|
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)