High‐temperature multilayer actuators based on CuO added BiScO₃–PbTiO₃ piezoceramics and Ag electrodes

Abstract

High‐temperature multilayer actuators based on Cu doping 0.367BiScO3–0.633PbTiO3 ceramic slices and Ag electrodes were prepared by low‐temperature co‐firing technology. The 0.3 wt% CuO addition has effectively reduced the sintering temperature of the ceramic from ~1080 to 930°C, thus the multilayer actuator were sintered at 930°C which is lower than the Ag melting point, that is, 961°C. The 4.3 mm thick multilayer actuator is composed of a series of ~44‐μm‐thick ceramic slices and ~2‐μm‐thick Ag electrodes. As a result, a ≥0.13% strain with nm‐scale preciseness can be produced in the actuator by 200 V driving voltage not only at room temperature but also at a high temperature up to 200°C. This actuator is essential for industrial machinery that requires nm‐scale position control at 20‐200°C.

Refreshing doping concept in perovskite piezoceramics: Composite modulation hidden behind lattice substitution

“…Further comparison with the densely sintered pure samples at 1050°C 20 reveals that the piezoelectric properties of the Cu 1+ -doped PZN-PZT samples sintered at 890°C still maintain a leading edge; this will benefit in the manufacturing of multilayer piezoelectric devices cofired with the low-cost all-silver internal electrodes. 32,33 We believe that there must be other mechanisms for improving the piezoelectric performance of Cu 1+ -modified samples. The grain size effect that generally affects piezoelectric performance was dismissed, 34 because the change in grain size of the PZN-PZT samples doped with different amounts of copper was small ( Figure 2F reveals the origin of high piezoelectricity, 4 in which P s is the spontaneous polarization, ε is the dielectric constant, and Q is the electrostrictive coefficient, a parameter generally insensitive to changes in the composition.…”

“…Under the same sintering temperature of 890°C, the x = 0.25 sample has d 33 of 402 pC/N; this is 63% larger than that of the x = 0.00 sample. Further comparison with the densely sintered pure samples at 1050°C 20 reveals that the piezoelectric properties of the Cu 1+ ‐doped PZN‐PZT samples sintered at 890°C still maintain a leading edge; this will benefit in the manufacturing of multilayer piezoelectric devices cofired with the low‐cost all‐silver internal electrodes 32,33 …”

Giant Bulk Photostriction and Accurate Photomechanical Actuation in Hybrid Perovskites

“…It is believed that MA organic structure in the tetragonal MAPbI 3 crystals exhibits an order‐disorder phase transition which introduces a nonzero but small electric polarization, leading to the formation of polar nanodomains. [ 41–46 ] These local polarized regions would be very helpful for suppressing the carrier scattering. Similar scenarios were once proposed by Zhu et al., and it was believed that the screened Coulomb potential created by large polarons in the crystal can reduce the carrier scattering by charged defects and phonons.…”

Piezoelectricity in Excess of 800 pC/N over 400 °C in BiScO3–PbTiO3–CaTiO3 Ceramics

“…At first, the BS–PT– x CTO ceramics show a high T C of ∼449 °C at x = 0, 441 °C at x = 0.005, 429 °C at x = 0.01, and 420 °C at x = 0.03, according to the relative permittivity (ε r ) and dielectric loss (tan δ) versus temperature curves (Figures S3 and S4). , Then, the high-temperature stability of d 33 was also evaluated after annealing these ceramics at 50–460 °C for 1 h and cooling down again to room temperature. As shown in Figure a, the room-temperature d 33 values of BS–PT– x CTO ceramics gradually decrease with the annealing temperature increasing from 20 °C to ∼400 °C, and then quickly decrease to zero at a temperature which is slightly lower than the T C .…”

“…The 0.364BiScO 3 –0.636PbTiO 3 – x CaTiO 3 (BS–PT– x CTO) with x = 0–0.03 ceramics were prepared by the traditional solid-state method. High-purity Bi 2 O 3 (99.9%, Aladdin, Shanghai), Sc 2 O 3 (99.9%, Alfa Aesar, Shanghai), PbO (99.99%, Alfa Aesar, Shanghai), TiO 2 (99.9%, Aladdin, Shanghai), and CaCO 3 (99.99% Aladdin, Shanghai) powders were weighed according to the BS–PT– x CTO chemical formula . These powders were ball-milled for 12 h, dried at 120 °C, calcined at 800 °C for 2 h, ball-milled twice, and dried again.…”