Alpha hematite (α-Fe2O3) has been considered to have only a poor sensitivity to reducing gases. However remarkable gas sensitive properties were observed in the α-Fe2O3 prepared from iron salts containing sulfate ion (SO4 -) by hydrolysis and precipitation. The sulfate ion remains in the α-Fe2O3 but vaporizes at near 760°C. The vaporization causes crystallization of the α-Fe2O3 and consequently results in a decrease in gas sensitivity. The sulfate ion is an extremely important factor in controlling the microstructure and plays a significant role in the gas sensitive properties of the α-Fe2O3 ceramics.
No takes yet. Share an insight, caveat, or question.
Nakatani et al. (1982) studied this question.
Synapse has enriched 5 related papers. Consider them for comparative context: