J. Phys. IV France 7 (1997) C2-1225-C2-1226
The Effect of Hydrostatic Pressure on the Local Structure of K1-xNaxTaO3 and KTa1-xNbxO3F. Wang, B. Ravel, Y. Yacoby, E.A. Stern and R. Ingalls
Department of Physics, FM-15, University of Washington, Seattle WA 98195, U.S.A.
We report the effect of hydrostatic pressure on the local structural distortions in K0.15Na0.85TaO3 and KNb0.87Ta0.13O3. The results show that as expected the unit cell dimensions and the Nb off center displacements decrease with increasing pressure. In contrast the oxygen rotation angles in K0.15Na0.85TaO3 increase with pressure. We also observe an anomalous increase in the Nb - 4th oxygen Debye-Waller factor which shows that pressure can induce disordered oxygen octahedra rotations in a crystal with no such rotations at ambient pressure.
© EDP Sciences 1997