Authors : Priyanka Biradar; Vijendra A. Chaudhari

Volume/Issue : Volume 11 - 2026, Issue 7 - July

Google Scholar : https://tinyurl.com/yp2zed5y

Scribd : https://tinyurl.com/4mudnzkk

DOI : https://doi.org/10.38124/ijisrt/26jul1094

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Abstract : Mn₃O₄ thin films are valuable materials for gas sensors, optoelectronic and energy storage devices, where intended doping provides a means to optimize their structural and optical characteristics. In this work, the effect of 5 at.% cobalt doping concentration in Mn₃O₄ thin films synthesized via spray pyrolysis is studied. Both undoped and Co-doped films were deposited on glass substrates at 400 °C. The 20 mL precursor solution was sprayed at a 2 mL/min flow rate under an air pressure of 30 psi, producing uniform nanocrystalline layers. Structural properties were analyzed using X-ray diffraction (XRD), while optical properties were assessed using UV–Visible spectroscopy. The absence of any extra peaks in the XRD pattern indicated the phase-pure formation of Mn3O4in both samples. Introduction of Cobalt resulted in a slight reduction in lattice parameters, which confirmed successful doping within the Mn3O4 structure. However, an increase in crystallite size upon doping indicated enhanced grain growth. Results of UV–Vis spectroscopy showed a minor decrement in bandgap energy from 2.58 eV for pure Mn₃O₄ to 2.34 eV for the 5% Co-doped film. Consequently, cobalt doping altered the electronic structure. Thus, the results show that spray pyrolysis is an effective route for the synthesis of high-quality Mn₃O₄ thin films with optimizable properties.

Keywords : Co-Doped Mn₃O₄, Hausmannite Thin Films, Spray Pyrolysis, Lattice Contraction, Bandgap Narrowing, XRD Microstructure, Manganese Oxide.

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