LAUSR

The aging characteristics and thermal stability of [001]c- and [111]c-poled tetragonal 0.63Pb(Mg1/3Nb2/3)O3–0.37PbTiO3 single crystals have been studied. For [001]c-poled crystal, the d33, $$\varepsilon _{{33}}^{T}$$ε33T, kt, and k33 increase slightly during the aging process due to the gradual depolarization of the single-domain state. On the contrary, the electromechanical properties of [111]c-poled crystal decrease quickly with the aging time due to the growth and combination of micro-domains. The temperature-dependent electromechanical properties indicate that the [111]c-poled multi-domain crystal is more stable than [001]c-poled single-domain crystal. In addition, the second poling can effectively enhance the piezoelectric constant d33 of the [111]c-oriented multi-domain crystals from 1032 pC/N after the first poling to 1247 pC/N.