Hj. Schmutzler et al., FABRICATION OF DENSE, SHAPED BARIUM CERATE BY THE OXIDATION OF SOLID METAL-BEARING PRECURSORS, Journal of the American Ceramic Society, 79(6), 1996, pp. 1575-1584
Some rare-earth-doped alkaline-earth cerates (e.g., Nd2O3-doped BaCeO3
) are proton conductors that can act as solid-state electrolytes in hy
drogen or steam sensors, hydrogen pumps, steam electrolyzers, and fuel
cells. In the present study, dense tapes of neodymia-doped barium cer
ate were produced by the oxidation of malleable Ba-CeH3-Nd2O3 precurso
r tapes. Precursor tapes were produced by cold-rolling either blended
or milled mixtures of Ba, CeH3, and Nd2O3 within a silver can. X-ray d
iffraction, electron micro-probe analyses, and thermogravimetric analy
ses were used to study the phase transformations resulting from heat t
reatments conducted at 300 degrees to 900 degrees C in pure, flowing o
xygen. Barium peroxide and cerium dioxide, produced during oxidation a
t less than or equal to 300 degrees C, reacted at greater than or equa
l to 500 degrees C to form barium cerate. The rate of formation of bar
ium cerate depended on the degree of milling of the solid metal-bearin
g precursor powder. Dense barium cerate tapes were obtained after heat
treatment at 1080 degrees C.