Dielectric and pyroelectric properties of the morphotropic phase boundary lead barium niobate (PBN) single crystals at low temperature (10–300 K)

Abstract

Low-temperature (10–300 K) dielectric and pyroelectric properties of morphotropic-phase-boundary lead-barium-niobate tungsten-bronze ferroelectric single crystals have been investigated. Strong ‘‘Debye-like’’ dielectric dispersion, along a nonpolar direction (perpendicular to the polarization direction), has been observed and characterized by dielectric spectrum techniques. A direct charge measurement method has been used to study the low-temperature pyroelectric properties in polar and nonpolar directions. A ‘‘frozen-in’’ polarization component in a nonpolar direction is also reported. The low-temperature relaxation effects are explained by the internal reorientation polarization perturbation and a thermally agitated local dipole fluctuation model.