DIELECTRIC AND PYROELECTRIC PROPERTIES OF THE MORPHOTROPIC PHASE-BOUNDARY LEAD BARIUM NIOBATE (PBN) SINGLE-CRYSTALS AT LOW-TEMPERATURE (10-300 K)

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.