Pyroelectric properties of (1−x)Pb(Mg1∕3Nb2∕3)O3-xPbTiO3 and (1−x)Pb(Zn1∕3Nb2∕3)O3-xPbTiO3 single crystals measured using a dynamic method

Abstract

The pyroelectric coefficients of $0.72\mathrm{Pb}\left({\mathrm{Mg}}_{1∕3}{\mathrm{Nb}}_{2∕3}\right){\mathrm{O}}_3\text{-}0.28{\mathrm{PbTiO}}_3$ (PMN-28PT), $0.67\mathrm{Pb}\left({\mathrm{Mg}}_{1∕3}{\mathrm{Nb}}_{2∕3}\right){\mathrm{O}}_3-0.33{\mathrm{PbTiO}}_3$ (PMN-33PT), and $0.92\mathrm{Pb}\left({\mathrm{Zn}}_{1∕3}{\mathrm{Nb}}_{2∕3}\right){\mathrm{O}}_3\text{-}0.08{\mathrm{PbTiO}}_3$ (PZN-8PT) single crystals, oriented and poled along three different crystallographic directions, ${\left[001\right]}_C$ , ${\left[011\right]}_C$ , and ${\left[111\right]}_C$ , have been measured using a dynamic method. The suffix $C$ indicates reference to the prototypic cubic coordinate system. Large coefficients of up to $1070\mu {\mathrm{C}\mathrm{m}}^{-2}{\mathrm{K}}^{-1}$ have been observed for the ${\left[111\right]}_C$ oriented, rhombohedral PMN-28PT and PMN-33PT samples, where the measurement direction corresponds to the polar axis of the crystal. For each composition and orientation two different poling procedures are compared, a commonly used field cooling method and a low temperature poling protocol. It was found that in otherwise pseudoorthorhombic samples of PZN-8PT, a room temperature rhombohedral phase could be stabilized by application of a field along the ${\left[111\right]}_C$ direction while heating from $-70°\mathrm{C}$ .