Wet chemical synthesis of hematite: Its magnetic property and sensing activity

Abstract

Iron oxide is well known for its applications in materials science and also in biology. Hematite i.e. α-Fe₂O₃ is the most stable form among several polymorphs of iron oxide. This study connects the synthesis of hematite via a simple reproducible route, its magnetic property and sensing capacity towards isopropyl alcohol. Here, citrate and hexamine are used as stabilizing agents. The intermediate product has evidence of their presence which on calcination forms α-Fe₂O_3. Detailed characterization using multiple techniques establishes the formation of α-Fe₂O₃. A detailed field dependent and temperature dependent magnetic measurements reveal an interesting behaviour of α-Fe₂O_3, above and below the Morin transition temperature. This α-Fe₂O₃ has good sensing capacity for several volatile organic compounds (VOCs) just at room temperature, isopropyl alcohol shows the best sensing response. The sample is prepared using easy drop casting method and the sensing device used here has shorter Response and Recovery time.