Mechanical Confinement: An Effective Way of Tuning Properties of Piezoelectric Crystals

作者：Marsilius Mie^*; Frederick Josh; Hu Wei; Tan Xiaoli; Granzow Torsten; Han Pengdi

来源：Advanced Functional Materials, 2012, 22(4): 797-802.

DOI：10.1002/adfm.201101301

• piezoelectric single crystals
• compressive pre-stresses
• domain switching
• coercive field
• remanent polarization

Using %26lt; 001 %26gt;-oriented Pb(Mg1/3Nb2/3)O3PbTiO3 ferroelectric single crystals as a model material, the impact of mechanical confinements on polarization hysteresis, coercive field, and remanent polarization of relaxor-based piezocrystals is investigated. Comparative studies are made among rhombohedral and tetragonal single crystals, as well as a polycrystalline ceramic, under uniaxial and radial compressive pre-stresses. The dramatic changes observed are interpreted in terms of the piezoelectric effect and possible phase transitions for rhombohedral crystals, and ferroelastic domain switching and the piezoelectric effect for tetragonal crystals. Under radial compressive stresses, the coercive field for the rhombohedral crystal is observed to increase to 0.67 kV/mm and that for the tetragonal crystal is increased to 0.78 kV/mm. This is a 200% increase relative to the unstressed condition. The results demonstrate a general and effective approach to overcome the drawback of low coercive fields in these relaxor-based ferroelectric crystals, which could help facilitate widespread implementation of these piezocrystals in engineering devices.

• 出版日期2012-2-22