This work brings insights into the defect chemistry of YBZ solid solutions by measuring enthalpies of formation. We find a correlation between the obtained thermodynamic data and the known trend of the proton conductivity of YBZ solid solutions. This study is important for informed thermodynamic history-based materials selection and processing for specific applications.

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A combination of surface area analyzer and microcalorimetry was employed to investigate the in situ water uptake energetics and the mechanism of proton incorporation in yttrium-doped barium zirconate in the temperature range 200−400 °C. The BaZr 1−x Y x O 3 solid solutions are made with variable yttrium content (x = 10, 20, and 30 mol %) by a controlled oxidant-peroxo synthesis method. The water uptake increases as the partial pressure of water increases; however, no saturation in the hydration isotherm is observed, implying further reaction at higher p H 2 O . The results suggest three distinct regions of hydration energies as a function of water content. The first water uptake enthalpy values showed high exothermicity, −140, −158, and −157 kJ mol −1 for BaZr 1−x Y x O 3 (x = 10, 20, and 30 mol %), respectively, at 400 °C, and the strong exothermic contribution supports the dissociative incorporation of water. The stepwise in situ hydration energetics is essential to understand the mechanisms of water incorporation and the role of H 2 O uptake in transport properties.

Highly reactive lead zirconate titanate powders (PZT) with different compositions were successfully synthesized by the oxidant-peroxo method (OPM) and used to prepare dense ceramic samples with composition near to the morphotropic phase boundary (MPB) sintered at 1000°C for 2 h using a tubular conventional oven and a commercial microwave system. Crystalline phases were identified in the powder and ceramic samples by X-ray powder diffraction and FT-Raman spectroscopy at room temperature. The fractured surface of the ceramic sample showed a high degree of densification with fairly uniform grain sizes. Dielectric constants measured in the range from 30 to 500°C at different frequencies (1, 10 and 100 kHz) indicated a normal ferroelectric behavior regardless of the sintering method. Samples sintered by a microwave radiation (MW) method and composition near to the MPB region showed a maximum dielectric constant of 17.911 and an anomalous high Curie temperature of 465°C.