Size-dependent magnetic properties of manganese ferrite fine particles

Abstract
We have developed synthetic techniques involving coprecipitation of iron(III) and manganese(II) ions from aqueous solutions using NaOH to create single‐crystal, stoichiometric MnFe2O4 particles. The particle diameter could be varied between 5 and 25 nm by varying the metallic‐ion to hydroxide‐ion concentration ratio. Magnetic measurements revealed that the saturation magnetization decreased, the ferrimagnetic to paramagnetic transition broadened, and the apparent transition temperature increased, all with decreasing particle size.