LAUSR

Mesoporous amorphous-crystalline nanopowders of BaF2 with the specific surface area up to 34.8 m2/g were obtained using evaporation by a pulsed electron beam in vacuum. Influence of the thermal annealing of the BaF2 nanoparticles in air at the temperatures from 200 to 900°C on the size and morphology of the particles and changes in their magnetic and luminescent properties was studied. The paramagnetic response of the BaF2 nanopowder was found to transform to the ferromagnetic response after annealing at 900°C. The appearance and transformation of the magnetic response in nanopowders made of BaF2, which is diamagnetic as the bulk material, are ascribed to the appearance of radiation-induced and structural defects during the synthesis process by pulsed electron-beam evaporation.