Enthalpies of Formation of Lead Zirconate Titanate (PZT) Solid Solutions

Microstructures of coherent phase decomposition near morphotropic phase boundary in lead zirconate titanate

“…1 Recently, an extended thermodynamic theory of PZT solid solution was formulated, 2 which treats PZT system as a regular solution and combines the conventional Landau-Ginzburg-Devonshire ͑LGD͒ free energy function 11 with positive enthalpy of formation 12 and entropy of mixing.…”

“…A value of w = 0.5k B T C / ⍀ is used for the positive enthalpy of mixing. 2,12 The simulation is performed with 512ϫ 512 computational cell with grid size of ϳ2 nm.…”

Thermodynamic Assessment of the PZT System

“…Figure 7 shows the calculated enthalpy of formation of the bPbZr x Ti 1 x O 3 solid solutions from oxides at 298 K as compared with experimental data of Rane and Navrotsky. 27 The measured enthalpies show the regular mixing behavior with the uncertainty of measurements, which is sometime higher than the measured values. However, when extrapolating these data to high temperatures the phase relations become inconsistent with the selected experimental information in the present work and the behavior of the ideal mixing is accepted.…”

“…The enthalpy of formation of PbTiO 3 using the drop solution calorimetry was measured by Rane and Navrotsky, 27 while the Mehrotra et al 38 as well as Shim and Jacob 39 measured the free energy of formation. The specific heat of pure lead titanate PbTiO 3 in the temperature range from 325 to 1250 K was studied by Rossetti and Maffei.…”

“…23 -26 Rane et al 27 reported the standard enthalpies and heat of mixing in the cubic lead zirconate titanate solid solutions using drop solution calorimetry . The Gibbs energy of the gas phase is given as…”