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Free keywords:
Pressure; Titanate
DDC:
550 - Earth sciences
Abstract:
The crystal structure of lead titanate PbTiO3 have been studied by energy-dispersive X-ray diffraction under pressures of 0–4 GPa in the temperature range of 300–950 K. At a temperature of T = 747 K, a structural phase transition from a ferroelectric tetragonal phase to a paraelectric cubic phase is observed. The application of pressure leads to a significant decrease in the phase transition temperature; under pressures of P ~ 2 GPa, the type of the phase transition changes from the first to second order. In the low pressure range, the baric coefficient value is dTc/dP = –20(3) K/GPa; under pressures above 2 GPa, it increases up to –113(5) K/GPa.
