Cold sintering and electrical characterization of lead zirconate titanate piezoelectric ceramics

Abstract

This paper describes a cold sintering process for Pb(Zr,Ti)O 3 ceramics and the associated processing-property relations. Pb(Zr,Ti)O 3 has a very small, incongruent solubility that is a challenge during cold sintering. To circumvent this, a Pb(NO 3) 2 solution was used as the transient liquid phase. A bimodal lead zirconate titanate powder was densified to a relative density of 89% by cold sintering at 300 • C and 500 MPa. After the cold sintering step, the permittivity was 200, and the dielectric loss was 2.0%. A second heat-treatment involving a 3 h anneal at 900 • C increased the relative density to 99%; the resulting relative dielectric permittivity was 1300 at room temperature and 100 kHz. The samples showed well-defined ferroelectric hysteresis loops, having a remanent polarization of 28 µC/cm 2. On poling, the piezoelectric coefficient d 33 was ∼200 pC/N. With a 700 • C 3 h post-annealing, samples show a lower room temperature relative permittivity (950 at 100 kHz), but a 24 h hold time at 700 • C produces ceramics where there is an improved relative dielectric constant (1050 at 100 kHz).

Current understanding and applications of the cold sintering process

“…6(c)). Similar phenomenon was also observed in CSP of Pb(Zr,Ti)O 3 [40]. A second phase, PbO, was found in as-CSPed sample, and the relative density was 89%.…”

“…For some ultra-stable compounds with very low solubility product constants (K sp ), such as Pb(Zr,Ti)O 3 , a transient solution containing corresponding cations can be used as an alternative to water or acid/alkali solutions in order to generate a saturated solution environment and form the same composites as final products. For example, Wang et al [40] used Pb(NO 3 ) 2 solution for densification of Pb(Zr,Ti)O 3 by CSP under 500 MPa at 300°C, and 89% of theoretical density was achieved. Moreover, to densify some ternary compounds with the cations having extremely large different dissolution properties, a suspension containing the cations and precursor oxide nanoparticles can be employed.…”

Recent Progress in Applications of the Cold Sintering Process for Ceramic–Polymer Composites

“…Determination of specific solvents is difficult but can be guided through consideration of solubility data and Pourbaix diagrams. Kinetics can also be aided with selection of particle size and particle size distributions of the ceramic phase . With multiple component ceramic compositions, binary, ternary, quinary compounds, etc., we have to be concerned with the relative rates of each chemical constituent, as this can lead to an incongruent dissolution.…”

Phase composition and dielectric properties of spark plasma sintered PbZr0.52Ti0.48O3

“…SPS is a useful tool to control parameters like grain size and porosity which play a fundamental role in dielectric response. Therefore, SPS method has been widely used to sinter PZT and doped PZT ceramic oxides for electrical applications [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36]. However, volatilization of PbO at higher temperatures (>600°C) may disrupt the stoichiometry of synthesized PZT ceramic oxide [22,27,31].…”