Formation of metal nanoparticles in MgF 2, CaF 2 and BaF 2 crystals under the electron beam irradiation and Fibers

 It is shown experimentally that electron beam action with electrons energies of 50 and 70 keV on MgF₂, CaF₂ and BaF₂ crystals results in local formation in the crystal near-surface layer of Mg, Ca or Ba nanoparticles which possess plasmon resonance. In the case of MgF₂ spheroidal nanoparticles are formed, in the cases of CaF₂ and BaF₂ – spherical. The formation of metal nanoparticles is confirmed by computer simulation in dipole quasistatic approximation. The dependence of absorption via electron irradiation dose is non-linear. It is caused by the increase of nanoparticles concentration and by the increase of nanoparticles sizes during irradiation. In the irradiated zones of MgF₂ crystals, for irradiation doses less than 80 mC/cm², the intense luminescence in a visible range appears. The practical application of fabricated composite materials for multilevel optical information recording is discussed.