We have investigated the dielectric anomalies associated with spin-ordering transitions in the tetragonal spinel Mn3O4 using thermodynamic, magnetic, and dielectric measurements. We find that two of the three magnetic ordering transitions in Mn3O4 lead to decreases in the temperature-dependent dielectric constant at zero applied field. Applying a magnetic field to the polycrystalline sample lea...

Antiparallel interlayer magnetic coupling between layers of Fe3O4 and Mn3O4 , both ferromagnetic, was reported in a recent study. The interlayer magnetic coupling may be affected by the magnetic property at the interface. In order to understand the interplay between the electronic configuration, the atomic structure and the magnetic property at the interface, we have performed transition metal ...

Mn3O4 were synthesized via the hydrothermal method at 200°C for 24 h, using surfactants. The resultant products examined by powder X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), transmission electronic microscope (TEM), UV-visible and BET surface area analysis. as-prepared materials used adsorption of methylene blue dye (MB). effect various experim...

Electron beam irradiation is well known to induce damage in materials. The structural transformation involved in the damage is usually believed to be an irreversible solid state chemical reaction. Here we use in situ transmission electron microscopy (TEM) combined electron-energy loss spectroscopy (EELS) technique in an aberration-corrected TEM to track the structural transformation in spinel M...

Previous measurements show that calcium manganese oxide nanoparticles are better water oxidation catalysts than binary manganese oxides (Mn3O4, Mn2O3, and MnO2). The probable reasons for such enhancement involve a combination of factors: The calcium manganese oxide materials have a layered structure with considerable thermodynamic stability and a high surface area, their low surface energy sugg...

Porous Mn3O4 hexagonal nanoplates were synthesized through annealing the hydrohausmannite precursor obtained by a one-pot hydrothermal process and by precisely controlling the concentrations of potassium hydroxide and glucose. The effect of potassium hydroxide and glucose on the growth of hexagonal nanoplates was investigated, and a growth mechanism was also proposed. Due to its abundant pores,...

The liquid phase oxidation of benzyl alcohol is an important reaction for generating benzaldehyde and benzoic acid that are largely required in the perfumery and pharmaceutical industries. The current production systems suffer from either low conversion or over oxidation. From the viewpoint of economy efficiency and environmental demand, we are aiming to develop new high-performance and cost-ef...