Crystallisation of LiPO3 glass was researched. The LiPO3 glass was obtained by a standard melt quenching technique from Li3PO4 and NH4H2PO4. The glass samples were devitrified by isothermal heat treatment. Products of LiPO3 glass devitrification at 425, 440 and 460 deg C were investigated with optimal microscopy and x-ray powder diffraction. It was found that Li4P4O12, LiPO3 and Li4P2O7 phases crystallise from the glass matrix under the investigated conditions. The sizes of the coherent diffraction domains of the studied samples were in the range of 400 to 2000 A, which indicates the presence of small sized crystals. The LiPO3 glass crystallisation mechanism was refined by comparing the degree of crystallinity and the proportion of the volume of the crystallisation region of the samples. The volume of the crystallisation region was determined from optical microphotographs. Surface crystallisation was predominant in this system.
