Magnetic properties of iron oxide nanoparticles in the matrix of potassium-aluminoborate glasses subject to thermoradiation treatment

Abstract

The paper presents the results of investigations of the magnetic properties of glasses of the composition K2O · Al2O3 · B2O3 (KAB) with the addition of Fe2O3 2.0 and 3.0 wt.subjected to radiation treatment in 60∘C gamma field at dose rate of 236 R/s for 2 hours at room temperature and when samples are heated to 423 K. Both under radiation and thermoradiation exposure, the magnetic susceptibility of glasses follows the Curie–Weiss law at 4.2–200 K and slightly deviates from this dependence at 200–340 K. The weakly pronounced magnetic hysteresis with low coercive force was detected at low temperatures against the background of magnetization that depends almost linearly on the field. An analysis of data on the temperature and field dependences of magnetization in weak and strong fields, combined with data on structural and optical properties, indicates that mainly Fe2O3 nanoparticles in the uncompensated antiferromagnetic state are formed in glasses, as well as an insignificant amount of dissociated Fe and Fe3O4 ions.