Synthesis of a magnetoactive compound based on iron(II) sulfate

The effect of synthesis parameters on properties of a magnetoactive compound (MAC) prepared via condensation of iron(II) sulfate in the presence of sodium nitrite is investigated. It is found that nitrite ions almost completely coprecipitate with the solid phase during the formation of a magnetoactive compound and subsequently participate in the redox conversions to yield magnetite. In order to obtain a magnetoactive compound with high relative magnetic susceptibility, condensation from the initial solutions is to be carried out at least 15 min after it is prepared; sodium nitrite consumption is to be at least 0.12 mol/mol FeSO 4 .