Abstract

To minimize pyroelectric effects while keeping high piezoelectric effects in relaxorPbTiO3 single crystals, the crystallographic orientation dependence of the pyroelectric and piezoelectric coefficients were investigated for binary (1  x)Pb(Mg1/3Nb2/3)O3xPbTiO 3 (PMNPT), ternary (1  x  y)Pb(In1/2Nb 1/2)O3yPb(Mg1/3Nb2/3)O 3xPbTiO3 (PINPMNPT) and Mndoped PINPMNPT single crystals with the "4R" multidomain state. The secondary pyroelectric coefficients were calculated from the thermodynamic interrelationship between the piezoelectric, elastic, and thermal expansion coefficients, being on the order of (1.161.23) × 104 C m2 K1 for binary crystals and (0.972.03) × 104 C m2 K 1 for ternary ones. The primary pyroelectric coefficients were (6.736.84) × 104 C m2 K1 and (5.446.43) × 104 C m2 K1 for binary and ternary crystals, respectively. The pyroelectric coefficients could be reduced by matrix rotation, but at the cost of decreasing longitudinal piezoelectric coefficients d33. Of particular interest is that the maximum piezoelectric coefficients d24â̂  at θ = ±55o and d34â̂  at θ = ±35 o by a counterclockwise rotation of θ about the X axis (θ is the rotation angle about the coordinate axes), or d15â̂  at θ = ±55o, and d35â̂  at θ = ±35o by a counterclockwise rotation the Y axis, were found on the order of 3000 pC N1. The corresponding pyroelectric coefficients could be reduced by ∼20%. The reduced pyroelectric coefficients that can contribute to decrease undesirable output signals, together with the high piezoelectric coefficients, enable relaxorPT crystals as favorable candidates for highsensitivity piezoelectric sensors. © 2014 Elsevier B.V.