Controllable vapor phase fabrication of F:Mn3O4 thin films functionalized with Ag and TiO2

Abstract

A facile two-step vapor phase synthetic approach is proposed for the fabrication of Mn₃O₄ thin films chemically modified with fluorine, and eventually functionalized with silver or titania. The adopted strategy exploits the initial chemical vapor deposition (CVD) of Mn₃O₄ on Si(100) substrates starting from a diamine diketonate Mn(II) complex, followed by the controlled radio frequency (RF)-sputtering of silver or titania. Complementary analytical techniques were employed to investigate the crystallinity (X-ray diffraction), chemical composition (X-ray photoelectron spectroscopy, secondary ion mass spectrometry, energy dispersive X-ray spectroscopy), morphology and nano-organization (field emission-scanning electron microscopy, atomic force microscopy, transmission electron microscopy) of both pristine and functionalized manganese oxide thin films. Under the adopted operating conditions, the target Mn(II) complex acted as a single-source precursor for both Mn and F, leading to the formation of phase-pure hausmannite Mn₃O₄ films characterized by a uniform in-depth fluorine content. In addition, the obtained results gave evidence of the formation of high purity Ag/F:Mn₃O₄ and TiO₂/F:Mn₃O₄ composites with a close contact between the single constituents. This work outlines an amenable and efficient method for the vapor phase growth of composite Mn₃O₄-based thin films, which are favorable candidates for diverse technological applications, from photocatalysis to gas sensing.