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Updated: Apr 16, 2026
Growth and Electrostatic/chemical Properties of Metal/LaAlO3/SrTiO3 Heterostructures
Published on: February 8, 2018
Crystal structure of A-site deficient La0.2Sr0.7-xCaxTiO3 perovskite at ambient conditions and high temperatures: a
Ahmed D Aljaberi1, John T S Irvine
1Mechanical and Materials Engineering Department, Institute Centre for Energy - iEnergy, Masdar Institute of Science and Technology, PO Box 54224, Abu Dhabi, United Arab Emirates.
Abstract:
The crystal structures of several members of the solid solution perovskite La(0.2)Sr(0.7-x)CaxTiO(3) were investigated using the Rietveld analysis of neutron powder diffraction patterns collected in ambient conditions and high temperatures. At room temperature, samples showed a tetragonal I4/mcm symmetry for compositions with 0.1 ≤x≤ 0.35 followed by a phase transition to the orthorhombic Pbnm symmetry for compositions with 0.4 ≤x≤ 0.7. Samples with the orthorhombic symmetry showed two reversible phase transitions in the temperature range 20 °C-900 °C. The first phase transition was a discontinuous Pbnm-I4/mcm around 300 °C and the second was a continuous I4/mcm-Pm3[combining macron]m transition around 900 °C. The lower symmetries resulted from very small distortions and changes in tilts of the BO(6) octahedra of this perovskite material; which was a direct result from the A-site ionic radius mismatch.
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