Effects of Pressure and Electric Field on the Relaxational Dielectric Properties of K$_{0.97}$Li$_{0.03}$O$_{3}$ (KLT-3)

ORAL

Abstract

The temperature dependence of the dielectric response of KLT-3 shows no evidence of a thermodynamic phase transition, but reveals two prominent relaxational features associated with the off-center Li$^{+}$ ion, one attributed to the hopping of the Li$^{+}$ dipole and the other with the reorientation of Li$^{+}$ - Li$^{+}$ ion pair. Both relaxations are Debye-like and follow Arrhenius kinetics, the energy barriers decreasing with pressure. While pressure favors the relaxational behavior, a biasing \textit{dc} electric field favors long-range order of the dipolar system. The interplay between pressure and field provides additional insight. Pressure suppresses the magnitude of the $\varepsilon \prime $(T) response over the whole temperature range The results allow evaluation of the contributions of the soft mode and of the Li$^{+}$ dipoles to the measured $\varepsilon \prime $(T) response.

*The work is supported by Division of Materials Sciences and Engineering, Office of Basic Energy Sciences, U.S. Dept. of Energy at Sandia under contract No.DE-AC04-94AL85000 and at Oak Ridge under contract DE-AC05-00OR22725.

Authors

  • George Samara

  • Robert Grubbs

  • Eugene Venturini

    • Sandia Labs
  • Lynn Boatner

    • Oak Ridge