Barium carbonate

Ba_0.85Ca_0.15Zr_0.1Ti_0.9O₃ (BCZT) powder was synthesized via a similar sol–gel route, according to Castkova et al. [29 (link)]. For solution A, barium carbonate (99%, Alfa Aesar, Haverhill, MA, USA) and calcium carbonate (≥99.0%, Sigma Aldrich, St. Louis, MI, USA) were dissolved in 5 M acetic acid under continuous stirring. For solution B, titanium(IV)-propoxide (97%, Sigma Aldrich), zirconium propoxide (70% in isopropyl alcohol, Alfa Aesar), and glacial acetic acid were added to ethanol under continuous stirring. Both solutions were mixed and aged overnight for a minimum of 12 h. The clear solution was heated until gelation and dried at 250 °C for 24 h. This xerogel was then calcined at 600 °C, 650 °C, 700 °C, 750 °C, and 800 °C for 5 h, respectively, to determine the appropriate calcination temperature.

Samarium Oxide (Sm₂O₃, 99.9%. Alfa Aesar), Barium Carbonate (BaCO₃, 99.0%, Alfa Aesar), Calcium Carbonate (CaO, 99.5%, Alfa Aesar), and Cobalt Oxide (Co₃O₄, 99.9%, Alfa Aesar) powder were used for the synthesis of SmBa_1-xCa_xCo₂O_5+d (SBCCO, x = 0.01, 0.03, 0.1, and 0.2) by solid state synthesis (SSR). Each powder was accurately weighed according to its chemical composition, and mixed using an agate mortar with a pestle and ethanol. The mixtures were placed in an oven and maintained at 78°C for 12 h to evaporate the ethanol. Mixtures were calcined for 6 h at 1000°C as a first calcination step to decompose all the carbonate. After that, materials were crushed by the agate mortar with the pestle and ball mill; then, a secondary calcination step was carried out for 8 h in an electric furnace at 1100°C in air atmosphere.
The chemical compositions and abbreviations in SmBa_1-xCa_xCo₂O_5+d (SBCCO, x = 0.01, 0.03, 0.1, and 0.2) of cathode materials are summarized in Table 1.
X-ray diffraction (XRD) patterns of the synthesized SmBa_1-xCa_xCo₂O_5+d (SBCCO, x = 0.01, 0.03, 0.1, and 0.2) oxide systems were obtained on a Model D/Max 2500, Rigaku (45Kv, 200mA, Cu kα radiation); the obtained data were matched with reference data for the phase synthesis and analyzed using the MDI JADE six program.