Effect of Pressure on Electromechanical Properties for PMN-PT Ceramics with Compositions near Morphotropic Phase Boundary

Author： Yasuda Naohiko

Publisher： Taylor & Francis Ltd

ISSN： 0015-0193

Source： Ferroelectrics, Vol.376, Iss.1, 2008-01, pp. : 81-88

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Abstract

The piezoelectric properties of PMN-PT ceramics with compositions near a morphotropic phase boundary were investigated under pressures p upto 150 MPa. The resonance and antiresonance frequency characteristics of impedance and phase in the k31 mode in the tetragonal phase for PMNT (67/33) and in the rhombohedral one for PMNT (69/31) ceramics were observed under various pressures. The resonance frequency fr remains almost constant and antiresonance one fa tends to increase with increasing p. The electromechanical coupling coefficient k31 in the k31 mode increases and the electromechanical quality factor Q decreases with increasing p. The decrease in Q with p is due to ferroelectric domain wall motions. The relative permittivity εr increases with increasing p. Such an increase in both k and εr dependent on p seems to be related to the decrease in ferroelectric domain size.