Structure-Properties Correlation of Lead Selenide-Lead Selenite Composite

Abstract

The main areas of work are related to the synthesis of a two-phase composite (1-x)PbSe·xPbSeO3 in the form of a powder, faceted single crystal, film and compacted material with the possibility of changing the fraction (x) of the PbSeO3 phase from 0 to 1 by oxidation of PbSe in a dry atmosphere in the temperature range 20-550 °С and the study of its physicochemical properties. All initial samples are obtained by the original method from Pb1-ySey powder, in which the composition corresponds to the maximum melting temperature of the compound and is defined as ysmax=0.500025±0.000025 at. Se. The powder is crushed, after which homogenizing annealing is performed at a constant temperature (~750 °C) in a dynamic vacuum in order to achieve the minimum general pressure condition. The noted precursor-related technological procedures are necessary to achieve congruent evaporation conditions in all types of samples and help minimize the concentration of inherent defects and inclusions in phase two. Depending on application, it is possible to form crystalline powders with a given ratio of volumetric phases PbSe and PbSeO3 in a separate grain. For all cases, the "shell" for semiconductor particles PbSe is the dielectric phase PbSeO3. The principal possibility of forming the smallest (up to nanometer) grains of lead selenide in the dielectric matrix of lead selenite is shown. According to the proposed method, the synthesis of lead selenite by oxidation of lead selenide is possible.