Аннотация:The structure and spectral-luminescent properties of solid solutions in the PbF 2 –EuF 3 and PbF 2 –ErF 3 systems obtained by both solid-phase reaction and co-precipitation from solutions are investigated. Nanopowders of compositions Pb 1-x Eu x F 2+x or Pb 1-x Er x F 2+x with a size of 40 nm were obtained by co-precipitation. The boundaries of the existence of a solid solution at a high and low temperature are determined. The differences in the luminescence spectra for solid solutions obtained by different methods are studied.