HIGH-PRESSURE STRUCTURAL STUDIES OF MOH LAYERED COMPOUNDS (M=NA, K, RB, CS)

The structures of alkali metal (Na, K, Rb, Cs) hydroxides were investi gated using energy-dispersive x-ray diffraction at pressures up to 20 GPa. The phase transitions previously discovered with optical methods (by Krobok and co-authors in 1992 and 1994) are confirmed. A structure is proposed for the high-pressure phases of KOH and RbOH, and for a p redicted. phase of CsOH. Equation of state parameters are presented fo r the phases encountered.