(NaCl)_x(KCl)_{y-x}(KBr)_{1-y} single crystals: study of the ac conductivity activation energy

TL;DR

This study investigates the ac conductivity activation energy in mixed alkali halide crystals, revealing a linear relationship with bulk modulus and mean atomic volume depending on composition.

Contribution

The paper introduces a classification of mixed alkali halide crystals based on their ac conductivity activation energy behavior relative to bulk modulus and atomic volume.

Findings

Activation energy varies nonlinearly with composition.

Three categories of mixed crystals identified based on major constituent.

Linear relationship between activation energy and BΩ in each category.

Abstract

Ac electrical measurements have been reported for alkali halide mixed crystals that were melt grown from NaCl, KCl and KBr starting materials. They showed a nonlinear variation of all the electrical parameters with the bulk composition. Here, we show that these mixed systems, depending on their major constituent, are classified into three categories in each of which, the activation energy for the ac conductivity increases linearly with B$\Omega$, where B is the isothermal bulk modulus and $\Omega$ the mean volume per atom.