Mn3O4 Nanoparticles: Synthesis, Characterization, and Dielectric Properties

Abstract

Mn3O4 nanoparticles were prepared by a simple chemical route using cetyltetramethylammonium bromide (CTAB) as a template agent. Mn3O4 nanocrystals present an octahedral shape, and their crystallite size varies between 20 and 80 nm. They were characterized by XRD, SEM, DTA/TG, and IR spectroscopy. XRD studies confirm the presence of a highly crystalline Mn3O4 phase. The Rietveld refinement of the X-ray diffraction data confirms that Mn3O4 nanoparticles crystallize in the tetragonal system with space group I41/amd. DTA/TG and XRD measurements demonstrate the phase transition toward a spinel structure between 25 and 700∘C . The electrical conductivity increases between 80 and 300∘C , suggesting a semiconducting behaviour of Mn3O4 . Both dielectric dispersion (ε′) and dielectric loss (ε′′) were investigated from 80 and 300∘C in the frequency range of 10 Hz–13 MHz. The dielectric properties showed typical dielectric dispersion based on the Maxwell-Wagner model.