Calorimetric study of ferroelectric BaTiO3 in cubic phase

Specific heat of barium titanate single crystals of different quality has been precisely measured with special attention to the temperature region above the ferroelectric phase transition. It was assumed that excess specific heat in the paraelectric phase has a fluctuation nature and the experimental data were analyzed in the framework of Levanyuk's theory for multiaxial ferroelectrics. Within this approach the correlation parameter δ is estimated to be 0.66 × 10-16 cm2 for Remeika-type crystals and 0.45 × 10-16 cm2 for TSSG (top-seeded solution growth) crystals. These values are in good accordance with earlier estimations.