Elastic, Dielectric and Piezoelctric Coefficients of Domain Engineered 0.70Pb(Mg1/3Nb2/3)O3-0.30PbTiO3 Single Crystal

A complete set of elastic, dielectric and piezoelectric coefficients for the domain engineered 0.70Pb(Mg1/3Nb2/3)O3‐0.30PbTiO3 [PMN‐30%PT] single crystal was measured by a hybrid method combining ultrasonic and resonance techniques. At room temperature, the PMN‐30%PT single crystal has rhombohedral symmetry. After being poled along [001] of the cubic axes, four degenerate domain states are present, which means that the system is macroscopically pseudotetragonal. The complete data set of material constants was determined for this domain engineered system based on the effective tetragonal 4mm symmetry. The sources of experimental errors and the error propagation for derived constants were analyzed in detail. Based on the analysis, an improved characterization scheme was formulated to minimize the relative errors of derived constants. In this optimized scheme, the elastic stiffness coefficients under constant electric field cijE , piezoelectric stress coefficients dij and dielectric permittivities under constant stress εijT were first determined, from which all other constants were derived to ensure self‐consistency of the data set. It was found that the electromechanical coupling coefficient k33 for the domain engineered sample is about 92% and the piezoelectric constant d33 is 1980 pC/N. Because PMN‐30%PT composition is slightly away from the Morphotropic Phase Boundary (MPB), its properties exhibit much better stability. An overall comparison among all measured data sets for the domain engineered PMN‐PT and PZN‐PT single crystals is provided.