Magnetic Properties of Iron Oxide Nanoparticles in the Matrix of Potassium–Aluminoborate Glasses Subjected to Thermoradiation Treatment
Abstract
The paper presents the results of studying magnetic properties of the K $${}_{2}$$ O $$\cdot$$ Al $${}_{2}$$ O $${}_{3}\cdot$$ B $${}_{2}$$ O $${}_{3}$$ (KAB) glasses with the addition of 2.0 and 3.0 wt $$\%$$ Fe $${}_{2}$$ O $${}_{3}$$ , subjected to radiation treatment in $${}^{60}$$ Co gamma-field at a dose rate of 236 R/s for 2 h at room temperature and when the samples are heated to 423 K. Under both 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 found at low temperatures against the background of magnetization that depends almost linearly on the field. The analysis of data on the temperature and field dependences of magnetization in weak and strong fields, combined with data on structural and optical properties, indi-cates that mainly Fe $${}_{2}$$ O $${}_{3}$$ nanoparticles in the uncompensated antiferromagnetic state, as well as an insignificant amount of dissociated Fe and Fe $${}_{3}$$ O $${}_{4}$$ ions, are formed in glasses.