Fast luminescence of sulfates of alkali-metals and alkali-earth-metals

In K2SO4, (NH4)2SO4, Rb2SO4, SrSO4 under excitation by impulse electron beams (300 keV, 100 A/cm2, 3 nc) the fast luminescence (τ<2 nc) has been revealed. Luminescence spectra in K2SO4, (NH4)2SO4, Rb2SO4 shows presence of luminescence bands with sharp pronounced maximums at 5.8 and 3.8 eV, which insensitivity does not depend on sample's temperature within interval 80-300 K. In K2SO4 the 5.8 and 3.8 bands effectively exciting at liquid helium temperature with photons energy >15 eV. During investigation these radiation bands were interpreted as radiation electron transitions between sub zones states of fissioned valency zone. It was suggested, that 5.8 and 3.8 luminescence bands are fundamental ones, inheriting to sulfates having β-K2SO4 crystallographic structure with D2h16-Pmcn spatial symmetry group. In same time in sulfates with different crystallographic structure the similar luminescence bands were not revealed. In SrSO4 crystal excited by impulse electron beam (300 keV, 100 A/cm2, 3 nc) measurement of fast luminescence band reveals single maximum at 4.7 eV. Measurement of temperature dependence shows that fast luminescence 4.7 eV putting out at 300 K. Nature of radiation bands under optical excitation in these materials are discussed