Abstract: Pure and Al doped α-Fe₂O₃ materials were prepared by a solution phase controlled hydrolysis me-thod, and were characterized by XRD, SEM and ICP techniques. Gas-sensing properties were carried out on gas sensors from these materials under laboratory and humid conditions. The experiments indicate that the crystalline size of Al doped α-Fe₂O₃ materials is less than that of pure one, and their conductivity increases obviously; the resultant Al doped Fe₂O₃ gas sensor exhibites a high response and a short response/recovery time in the detection of low concentrations of various combustible gases. The Al doped Fe₂O₃ sintered at 400 ℃, which is more stable than one sintered at 300 ℃, is suitable as a gas sensor for ethanol alcohol.

Key words: Al doped, α-Fe₂O₃, Gas sensor, Combustible gas