Effect of annealing in different media and pulse electron beam irradiation on the properties of calcium fluoride nanopowder

Using the method of evaporation by pulsed electron beam in vacuum the mesoporous nanopowder of CaF2 with a specific surface area up to 91.5 m2/g was produced. The effect of annealing in different media and irradiation with a nanosecond electron beam (700 keV) on the evolution of the magnetic, luminescent and textural properties of CaF2 nanoparticles have been studied. For the first time, a joint effect of the annealing medium and the absorbed dose of a relativistic electron beam irradiation on the specific surface area and magnetization of mesoporous nanopowders of the CaF2 was discovered, which confirms the defective nature of ferromagnetism at room temperature of CaF2 nanopowders. The effect of nanopowder surface properties on ferromagnetism at room temperature after annealing in different media is shown, a parameter for assessing this influence is proposed. It was found that annealing and irradiation caused a significant change only in the visible range, of the pulse cathodoluminescence spectra of the CaF2 nanopowder, with the temperature and medium of the nanopowder pre-annealing as well as the irradiation dose being important. The relationship between luminescent and magnetic properties of nanopowder was shown.