The Synthesis and Characterisation of the High-Hardness Magnetic Material Mn[sub.2]N[sub.0.86]

High-quality P6[sub.3]22 Mn[sub.2]N[sub.0.86] samples were synthesised using a high-pressure metathesis reaction, and the properties of the material were investigated. The measurements revealed that the Vickers hardness was 7.47 GPa, which is less than that predicted by commonly used theoretical models. At low air pressure, Mn[sub.2]N[sub.0.86] and MnO coexist at 500 to 600 °C, and by excluding air, we succeeded in producing Mn[sub.4]N by heating Mn[sub.2]N[sub.0.86] in nitrogen atmosphere; we carefully studied this process with thermogravimetry and differential scanning calorimetry (TG-DSC). This gives a hint that to control temperature, air pressure and gas concentration might be an effective way to prepare fine Mn-N-O catalysis. Magnetic measurements indicated that ferromagnetism and antiferromagnetism coexist within Mn[sub.2]N[sub.0.86] at room temperature and that these magnetic properties are induced by nitrogen vacancies. Ab intio simulation was used to probe the nature of the magnetism in greater detail. The research contributes to the available data and the understanding of Mn[sub.2]N[sub.0.86] and suggests ways to control the formation of materials based on Mn[sub.2]N[sub.0.86].