ELECTRON MICROSCOPIC STUDY OF LEAD-BORATE COMPOSITES CONTAINING PbMoO_4 NANOCRYSTALS

摘要

Composite materials based on 2PbO.B_2O_3 (g-PbB) glass and crystalline PbMoO_4 (c-PbMo) are prepared by incorporation method combined with melting of mixtures from both components at different heat treatment times and cooling rates of the melts. The density of the samples is measured. The phase formation is studied by X-ray diffraction analysis. Using TEM structural changes are investigated in dependence on the composition, cooling rate and heat treatment time. It is established that the applied method reduces the gas inclusions and formation of micropores in the final materials. Fast cooled glassy samples with 5 and 10 wt% c-PbMo possess a background structure about 100nm. Aggregation trend is found in the samples containing over 20 wt% c-PbMo and crystallization, mixture structure of immis-cibility droplets and microcrystals and extracted c-PbMo are observed.