THERMODYNAMIC CALCULATION AND 3D MODELING T-x-y AND P(Se2)-T-x DIAGRAMS IN THE SYSTEM Cu–Pb–Se ON LIQUIDUS PbSe

Abstract

Abstract. From the condition that the chemical potentials of the components of the AB compound are equal in the equilibrium liquid and solid phases, taking as pure liquid components as the standard state, equations are obtained for calculating and modeling of partial excess thermodynamic functions, of the pressure-temperature-composition diagram and liquidus surfaces of the binary compound in the ternary system A–B–C. The equations obtained are tested on the Cu–Pb–Se system in the liquidus region of the PbSe compound. It is shown that the vapor phase mainly consists of two atomic molecules of selenium Se2. For the liquidus regions PbSe(p-type)-Se and PbSe(n-type)-Pb, the following dependences are obtained, respectively: lg Se p 2 (Pa) = [–1281 + 5624(1000/T) – 9190(1000/T)2 + 6648(1000/T)3 – 1797(1000/T)4] – 10.35 xCu 2 ; lg Se p 2 (Pa) = [2026 – 8778(1000/T) + 14247(1000/T)2 – 10259(1000/T)3 + 2759(1000/T)4] – 8.36 xCu2 . For the thermodynamics calculation and modeling of surface crystallization PbSe in the ternary system Cu -Pb-Se is obtained dependence: T = [ + ( - x ) Gexs (xl )] / [ . - . ln x ( - Cu. PbSe Se Se 110693 1 0 35D 25 695 8 31 1 xSe )] Where DGexs l PbSe , = –76057 + 335550,738хSe – 2,41759E6хSe 2 + 7,33249E6хSe 3 – 9,7868E6 хSe 4 + 4,69725E6хSe 5. 3D visualization of the obtained analytical dependencies is carried out with the help of a computer program OriginLab2017.

Keywords

• thermodynamics
• copper-lead-selenium
• liquidus of lead selenide
• vapor pressure of selenium
• 3D modeling.