Investigation of electromechanical properties and related temperature characteristics in domain-engineered tetragonal Pb(In_1/2Nb _1/2)O₃-Pb(Mg_1/3Nb_2/3)O ₃-PbTiO₃ crystals

The orientation-dependent electromechanical properties were calculated for tetragonal Pb(In_1/2Nb_1/2)O₃-Pb(Mg _1/3Nb_2/3)O₃- PbTiO₃ (PIN-PMN-PT) crystals based on single-domain data. The maximum electromechanical coupling was found to lie along the polar direction [001], whereas the maximum piezoelectric coefficient was found to occur along [011]. Subsequently, the piezoelectric properties of [011] poled tetragonal PIN-PMN-PT crystals, with an engineered domain configuration ("2T"), were studied using resonance impedance measurement and strain versus electric field (S-E) behavior, where the piezoelectric coefficient d₃₃ and coupling k₃₃ of [011] poled crystals were found to be on the order of 1000 pC/N and 0.75, respectively. The high d₃₃ of [011] poled crystals was associated with the high shear coefficient d₁₅ (∼2300 pC/N) in single domain state. Finally, the piezoelectric and electromechanical properties of [011] domain engineered tetragonal PIN-PMN-PT crystals were investigated as a function of temperature. In contrast to [001] single-domain PIN-PMN-PT crystals, the piezoelectric coefficient d₃₃ and coupling k₃₃ of [011] poled crystals were found to decrease with increasing temperature.