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Updated: Aug 10, 2025
High Pressure Single Crystal Diffraction at PX^2
Published on: January 16, 2017
High-Pressure X-ray Diffraction Study of Orthorhombic Ca2Zr5Ti2O16
Tania Garcia-Sanchez1, Daniel Diaz-Anichtchenko2, Alfonso Muñoz3
1Departamento de Ingeniería Eléctrica, MALTA Consolider Team, Universitat Politècnica de València, Camino de Vera s/n., Valencia, 46022, Spain.
Abstract:
The orthorhombic polymorph of Ca2Zr5Ti2O16 (space group Pbca) has been studied by powder X-ray diffraction under high pressures up to 30 GPa using synchrotron radiation. We have found evidence of a structural phase transition at 12-13 GPa. The phase transition causes an enhancement of the crystal symmetry. The high-pressure phase is tetragonal, being described by space group I41/acd. The space groups of the high- and low-pressure phases have a group/subgroup relationship. However, the phase transition is accompanied by a discontinuous change in the unit-cell volume, indicating that the phase transition can be classified as first order. We have also performed density functional theory calculations. These simulations support the occurrence of the orthorhombic-to-tetragonal transition. The pressure-volume equation of state and axial compressibilities have been determined for both polymorphs. The results are compared with previous studies in related oxides.
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