Specific heat and heat conductivity of BaTiO₃polycrystalline films in the thickness range 20–1100 nm

Abstract

Thermal properties - specific heat and heat conductivity coefficient - of\npolycrystalline BaTiO3 films on massive substrates were studied as a function\nof the temperature and the film thickness by ac-hot probe method. The anomalies\nof specific heat with decreasing of the film thickness from 1100 to 20 nm\nrevealed the reducing of critical temperature (Tc) and excess entropy of the\nferroelectric phase transition, which becomes diffused. The critical thickness\nof the film at which Tc = 0 estimated as 2.5 nm.\n