Mi. Gomez et al., Synthesis of AFeO(2.5+x)(0 <= x <= 0.5; A = Sr, Ca) mixed oxides from the oxidative thermal decomposition of A[Fe(CN)(5)NO]center dot 4H(2)O, J SOL ST CH, 142(1), 1999, pp. 138-145
The ion-temperature formation of Sr and Ca ferrates by thermal oxidative de
composition of tetrahydrates of Sr and Ca nitroprussides (pentacyanonitrosi
lferrates(II)) is reported. IR spectroscopy, X-ray diffraction (including R
ietveld analysis), and thermal analysis were used to follow the process. Th
e amount of active oxygen (concentration of Fe(IV)) in the products was che
mically determined. For the Sr compound, the final product was an oxygen-de
ficient perovskite that could be produced with a very low content of carbon
ate in the temperature range 750-850 degrees C. For the calcium compound, o
nly Ca2Fe2O5 with the brownmillerite type structure was obtained. (C) 1999
Academic Press.