Thermal studies of magnetic ferroelectrics in the system Pb(Fe0·5Nb0·5)O3-BiFeO3

摘要: The heat capacities of the compounds Pb(Fe05Nb05)O3, Bi02Pb08- (Fe06Nb04)O3, Bi04Pb06(Fe07Nb03)O3 and Bi06Pb04(Fe08Nb02)O3 were determined in temperature range 300-670 K with an adiabatic calorimeter that permitted a precision about 15% measurements. Experiments performed using intermittent heating technique order equilibrium might be obtained. curves specific against revealed anomalous behaviour at 374, 365, 424 492 Bi02Pb08(Fe06Nb04)O3, Bi04Pb06- (Fe0.7Nb0.3)O3 Bi0.6Pb0.4(Fe0.8Nb0.2)O3 respectively. transition enthalpies estimated to 828, 608, 756 540 cal mol−1 peaks Pb(Fe05Nb05)O3 Bi02Pb08(Fe06Nb04)O3 have been correlated their ferroelectric Curie points, those Neel points. Probable reasons for low values suggested. Thermodynamic functions such as enthalpy entropy evaluated over K.