Synthesis of vertically aligned manganese-doped Fe3O4 nanowire arrays and their excellent room-temperature gas sensing ability

Abstract

Vertically aligned Mn (10%)-doped Fe3O4 (Fe2.7Mn0.3O4) nanowire arrays were produced by the reduction/substitution of pregrown Fe2O3 nanowires. These nanowires were ferromagnetic with a Verwey temperature of 129 K. X-ray magnetic circular dichroism measurements revealed that the Mn2+ ions preferentially Occupy the tetrahedral sites, substituting for the Fe 31 ions. We observed that the Mn Substitution decreases the magnetization, but increases the electrical conductivity. We developed highly sensitive gas sensors using these nanowire arrays, operating at room temperature, whose sensitivity showed a correlation with their bond strength of diatomic/triatomic molecules.