Crystal structure and thermal expansion of PrGaO3 in the temperature range 10-1253 K
|Leonid Vasylechko 3, Anatoliy Senyshyn 3, Michael Knapp 2, Marek Berkowski 4, Carsten Paulmann 1, Ulrich Bismayer 1, A. Matkovskii 3|
1. University of Hamburg, Mineralogisch-Pertographisches Institut, Hamburg, Germany
Crystal structure and thermal expansion of PrGaO3 have been investigated in the temperature range 10-1253 K by means of single crystal and high-resolution powder diffraction techniques using synchrotron radiation. Single crystal and powder diffraction experiments were carried out at the beamlines F1 and B2 at HASYLAB/DESY. PrGaO3 possesses an orthorhombically distorted GdFeO3 type structure in the whole temperature range investigated. The changes in lattice parameters and cell volume are anisotropic and nonlinear with increasing temperature. Negative thermal expansion in - and -directions were detected in the temperature ranges 10-180 K and 10-50 K, respectively. Negative thermal volume expansion is observed in the temperature range 10-50 K. Due to pronounced anisotropy of the thermal expansion, the normalized values of the lattice parameters bp and cp become equal at 1200 K. For the average interatomic distances (PrO)8-(PrO)12, (GaO)6 and (OO)8 a linear increase with temperature is observed. For the temperature dependencies of the (PrPr)6, (PrGa)8 and (GaGa)6 average distances a change of slope occurs at 200-300 K.
Presentation: poster at E-MRS Fall Meeting 2003, Symposium B, by Leonid Vasylechko
See On-line Journal of E-MRS Fall Meeting 2003
Submitted: 2003-05-10 10:10 Revised: 2009-06-08 12:55