Electronic and magnetic properties of hausmannite

In this work, the magnetic and electronic properties of the mineral hausmannite (Mn₃O₄) have been studied using both experimental and theoretical methods. Magnetic susceptibility χ was measured in the paramagnetic region over the temperature range of 288−1000 K using the Faraday method. The anomalies recorded at 657 K and 898 K in the χ⁻¹ (T) plots were attributed to the Jahn-Teller effect, and this phenomenon was also found in the differential scanning calorimetry (DSC) analysis. Using the first-principles calculations based on the DFT+U method within the Quantum ESPRESSO package, the magnetic moment values of -4.1113 and 3.4801 Bohr magnetons (μB) for Mn²⁺ and Mn³⁺ ions, respectively, were obtained. The result of a net magnetization of 6.00 μB per cell was established which indicated the ferrimagnetic nature of the object. Band structure analysis confirmed the semiconductor nature of hausmannite (a theoretical band gap E_g ≈ 0,82 eV).