Opacity of KCl single crystal shocked above the transition pressure

Strong absorption of light by shock-transformed KCl (potassium chloride) si ngle crystal has been used for measurement of electrical conductivity of it s high-pressure B2 phase. The obtained conductivity values allow the determ ination of the width W of the gap between the valence and the conduction ba nds and its dependence W=W-0(1-b epsilon) on the compressive strain epsilon . The values of the gap width W-0=0.49 +/-0.06 eV and of the parameter b=1. 4 +/-0.4 lead to the conclusion that KCl in its high-pressure modification is a semiconductor. (C) 2001 American Institute of Physics.