Equation of state of BaTiO3 and KNbO3 at room temperature up to 30 GPa

Investigations under pressure and at room temperature of BaTiO3 and KNbO3 Using angle-dispersive powder X-ray diffraction are reported. Measurements were performed up to 35 and 30 GPa, respectively. The locations of the various transitions are consistent with other investigations. The variation of the cell volume was fitted to a Murnaghan type equation, the resulting bulk modulus B-0 is compared to the one computed from atmospheric Brillouin scattering data. A good agreement is obtained. (C) 2002 Elsevier Science Ltd. All rights reserved.