COMPRESSION OF KCL IN THE B2 STRUCTURE TO 56 GPA

The room temperature static compression of the high pressure B2 phase of KCl has been measured in a diamond anvil cell to 56 GPa. Birch-Murnaghan finite strain analysis extrapolated to zero pressure gives V02/V01 = 0.8483 +/- 0.0057 and K02 = 28.7 +/- 0.6 GPa, with K02' constrained to a value of four. Universal equation of state parameters are virtually identical. Although these results generally concur with previous work at lower pressures, significant differences exist in the zero pressure equation of state parameters extrapolated from the two sets of data. Recent ab initio structure calculations predict compressions in good agreement with our experimental results. Born models utilizing exponential repulsive potentials account well for the data, even over the large (50%) range of compression observed.