Longitudinal Piezoelectric Coefficient D33 Research Articles

The nonlinear, complex, induced-piezoelectric response of Pb(Mg1/3Nb2/3)O3–PbTiO3 relaxors

The amplitude-dependent complex piezoelectric response of Pb(Mg1/3Nb2/3)O3–PbTiO3 relaxors has been investigated using a single-beam interferometric technique as a function of ac electrical drive, superimposed dc electrical bias, and measurement frequency. Large-induced longitudinal piezoelectric coefficients (d33) were observed over a wide dc bias range below polarization saturation. On approaching polarization saturation, the value of d33 decreased, approaching values typical of poled piezoelectric ceramics. Investigations as a function of ac drive revealed the presence of strong nonlinearities, where the value of d33 increased with increasing drive. The nonlinear contribution was found to be on the order of 50% of the total response. In addition, large unexpected piezoelectric loss factors tan δ(piezo) were observed in materials which were otherwise characterized by anhysteresis in the polarization electric field behavior. The value of tan δ(piezo) was found to be in the range between 0.10 and 0.20, depending on various measurement conditions. With either increasing dc bias or ac drive, the value of tan δ(piezo) was found to decrease significantly.

Fabrication and Electrical Properties of Lead Zirconate Titanate Thick Films

Thick films of lead zirconate titanate of the morphotropic phase boundary composition, Pb(Zr0.52Ti0.48)O3, have been fabricated on platinum‐buffered silicon using a modified sol–gel spin‐coating technique. Crack‐free films of 12‐μm thickness can be uniformly deposited on 3‐in.‐diameter wafers with high yield and properties comparable to those of bulk ceramics. The thickness dependence of film structure and the dielectric, ferroelectric, and piezoelectric properties have been characterized over the thickness range of 1–12 μm. A strong (100) texture develops as film thickness increases above 5 μm; the films were marked by saturation values of longitudinal piezoelectric coefficient d33, 340 pC/N; remanent polarization, 27 μC/cm2; and dielectric permittivity, 1450. PZT films in this thickness range are extremely well‐suited to application as electromechanical transduction media in silicon‐based microelectromechanical systems (MEMS).

Fatigue of piezoelectric properties in Pb(Zr,Ti)O3 films

Piezoelectric properties of Pb(Zr,Ti)O3 thin films are investigated as a function of the number of bipolar (switching) and unipolar (nonswitching) voltage pulses. The longitudinal piezoelectric coefficient d33 decreases with bipolar fatigue reflecting the decrease of switchable polarization. Simultaneously, a strong vertical shift of piezoelectric hysteresis loops is observed, which is considered as the buildup of fixed internal polarization due to the pinning of ferroelectric domains in a preferred orientation. Piezoelectric fatigue induced by unipolar (nonswitching) pulses is considerably smaller than the fatigue under bipolar conditions and can be described by the internal bias field which shifts piezoelectric hysteresis loops along the field axis.

Dielectric, ferroelectric, and piezoelectric properties of lead zirconate titanate thick films on silicon substrates

This article reports the fabrication of thick films of lead zirconate titanate (PZT) on platinum-buffered silicon substrates by screen printing. Crack-free films, up to 12 μm on a single pass, show a dielectric permittivity of 200, tangent losses of 0.05, remanent polarization of 2.5 μC/cm2, and coercive field of 40 kV/cm. The field-induced longitudinal piezoelectric coefficient d33 at 40 kV/cm dc bias and 4 kV/cm alternating field corresponded to 50 pC/N. The magnitude of the piezoelectric voltage coefficient g33, computed from the strain coefficient and dielectric permittivity, under the same conditions, was found to be 36×10−3 V m/N, higher than that of a poled PZT bulk ceramic in comparison. These results are promising for a broad variety of sensor applications.

Dependence between stability and anisotropy of pzt piezoceramics and their orientational polarization

Abstract A theoretical model showing a dependence of the stabilizing processes under compression in PZT piezoceramics on the ratio of the longitudinal piezoelectric coefficient d33 over the transverse coefficient d31 is developped. The experimental results are compared with theoretical values based on this model.