GLASS FORMATION IN TERNARY SYSTEM La2O3–As2S3–Pr6O11

Abstract

Boundaries of glass formation in ternary system La2O3-As2S3-Pr6O11 were studied using methods of physical-chemical analysis (DTA, DTG, X-ray analysis, MSA). It was established that in glass formation region the range of concentration covers from As2S3-La2O3 15 mol%, but from As2S3-Pr6O11 it is 13 mol%. To our opinion the decrease in glass formation region of Pr6O11 comparing to La2O3 is related to crystalline structure of oxide, i.e. to the change in coordination number of lanthanides. Because properties of compounds of lanthanide are more sensitive to the change in coordination numbers relative to radii of ion. In the system the region of transparent glass formation is limited with the region of non-transparent one. The reason of non-transparency of a glass is the formation of primary centers of crystallization, which was confirmed by the results of X-ray analysis and SEM. Raman spectra of transparent glass containing(La2O3)0.07(As2S3)0.90(Pr6O11)0.03 were studied. Intensity of bands which characterize the bonds of As–S, La–O, Pr–O in Raman spectrum and shift of energy of waves in the big party are related to the strengthening of bonds and probably, appearance of new bonds in glasses. When heating glasses of the composition (La2O3)0.07(As2S3)0.90(Pr6O11)0.03 in inert atmosphere (He) at 224,61 °С it softens which is followed by endoeffects. Observed exoeffect at 315,80 °С satisfies crystallization of glass, but at 380,80 °С thermal decomposition begins. Samples in the region of glass formation are stable at 300 K to air, water and organic solvents. When heated, glasses are dissolved in chromic mixture. They decompose in mineral acids and alkalies.Forcitation:Bakhtiyarly I.B., Fatullayeva G.M., Kerimli O.Sh. Glass formation in ternary system La2O3–As2S3–Pr6O11. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 4-5. P. 43-48