Mn3O4 Nanoparticles: Synthesis, Characterization, and Dielectric Properties

Mn 3 O 4nanoparticles were prepared by a simple chemical route using cetyltetramethylammonium bromide (CTAB) as a template agent.Mn 3 O 4nanocrystals 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 crystallineMn 3 O 4phase. The Rietveld refinement of the X-ray diffraction data confirms thatMn 3 O 4nanoparticles 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 and700 ∘ C . The electrical conductivity increases between 80 and300 ∘ C , suggesting a semiconducting behaviour ofMn 3 O 4 . Both dielectric dispersion ( ε ′) and dielectric loss ( ε ′′) were investigated from 80 and300 ∘ C in the frequency range of 10 Hz–13 MHz. The dielectric properties showed typical dielectric dispersion based on the Maxwell-Wagner model.