Dielectric hysteresis from transverse electric fields in lead zirconate titanate thin films

Abstract

Excellent symmetric dielectric hysteresis is observed from lead zirconate titanate (PZT) thin films using transverse electric fields driven by interdigitated surface electrodes. The 1-μm-thick PZT films with a Zr/Ti ratio of 52/48 are prepared on ZrO2 buffered, 4-in.-diam silicon wafers with a thermally grown SiO2 layer. Both the ZrO2 buffer layer and PZT film are deposited by using a similar sol–gel processing. Remanent polarization of about 20 μC/cm2 with coercive field less than 40 kV/cm is obtained as measured using a triangle wave at 50 Hz. Thicker films are being developed and retention for the transversely polarized state is currently under study. One of the objectives of this study is to develop a large array of d33-driven unimorph sensing elements for a high-resolution acoustic imaging system.

Physical Kinetics of Ferroelectric Hysteresis

“…Both experimentally [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] and theoretically [19][20][21][22][23][24][25][26][27][28], the polarization can be changed in direction via a dynamic switching process accompanied by hysteresis [9,[28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47]. Some of the partially understood experimental properties of ferroelectric domains [27,[48]…”

Micro-fabricated flexible PZT cantilever using d33 mode for energy harvesting

“…The capacitance measured using an HP4194A is 0.23 nF and the extracted relative dielectric constant is 1243.4. In order to measure the dielectric properties, the effective area for the IDT electrodes was calculated as the product of the length of the comb fingers and the thickness of the PZT thin film [13,14]. Figure 6 shows the frequency responses of the fabricated energy harvesters using the polyimide based PZT cantilever.…”

Piezoelectric MEMS Power Generators for Vibration Energy Harvesting

“…This is achieved by optimizing the power with respect to the dimensionless constant, τ: It can be found that except the geometric dimensions, the output power is only the function of Ω, ζm and κ. For MEMS-scale devices, ζm is generally at least an order of magnitude smaller than κ2 [40]. With this assumption, the power output at both the resonance and antiresonance frequencies (under optimal electrical load) is approximated as:…”

“…With the assumption that for MEMS-scale devices, m is generally at least an order of magnitude smaller than 2 [40], the power output at both the resonance and antiresonance frequencies (under optimal electrical load) is approximated as:…”