Thermal magnetic hysteresis of nickel-doped pyrrhotites

The magnetic properties of polycrystalline natural pyrrhotite samples with low-nickel contents and synthesized Fe0.675Ni0.2S and Fe0.475Ni0.4S pyrrhotites are investigated. All of the investigated pyrrhotites are shown to have a thermal magnetic hysteresis in the region of 298–623 K. As a result, there is not only an increase in the difference between the magnetic moment values of the materials after a heating-cooling regime, but also a change in their magnetic state.