High Magnetic Coercivity in Nanostructured Mn₃O₄ Thin Films Obtained by Chemical Vapor Deposition

Nanostructured α-Mn3O4 (haussmannite) thin films consisting of evenly interconnected nanoaggregates were prepared on Si(100) substrates by chemical vapor deposition from a Mn­(II) diketonate-diamine precursor under different reaction atmospheres (dry vs wet O2) and total operating pressures. The combination of chemico-physical results obtained by the joint use of complementary techniques enabled us to demonstrate the obtainment of high-purity Mn3O4 materials free from other manganese oxide phases, characterized by controllable structural and morphological characteristics as a function of the adopted processing conditions. Magnetic properties were investigated by analyzing temperature dependence (i.e., field-cooled and zero-field-cooled measurements) and field-dependence of the magnetization behavior. The obtained films show bulk-like magnetic properties, together with extraordinarily high low-temperature in-plane coercivities (up to ∼1 T). The possibility to tailor these values by varying the content of microstructural defects may foster the implementation of the obtained films in eventual technological applications