Phase transition in potassium titanyl phosphate (KTP) under high pressure

Abstract

Raman scattering experiments on KTP (G.A. Kourouklis et al., 1987), indicate a phase transition to a lower symmetry phase around 6 GPa. To investigate the structure of this high pressure phase, we have carried out an energy dispersive x-ray diffraction study of the powdered sample using a diamond anvil cell and full diffraction cones of 5° and 6°. The data was analyzed in terms of the recently determined structure of the high pressure phase of KTP (Allen and Nelmes, 1992). We find that our experimental data is in full agreement and therefore confirm that KTP undergoes an iso-spacegroup transition at about 6 GPa.