10028-16-7Relevant academic research and scientific papers
Chemistry of mixed crystals in complex phase diagrams the system Bi2O3/Bi2Se3/Bi2Te 3
Schmidt,Oppermann
, p. 627 - 637 (2000)
The phase diagram of the pseudoternary system Bi2O3/Bi2Se3/Bi2Te 3 is found to include a quaternary solid solution Bi2O2(TexSe1-x) and ternary, intermetallic mixed crystals Bi2(TexSe1-x)3. Using thermodynamic modeling of the solid solutions it is possible to calculate complex heterogeneous equilibria between all phases of this phase diagram. As a result we can thermodynamically describe the observed phase relations: Bi2(Tex-Se1-x)3 ΔH°m(298) = 0; ΔS°m(298) = R [xlnx + (1-x)ln(1-x)] Bi2O2(TexSe1-x) ΔH°m(298) = Q ·(1-x); OΔS°m(298) = R/4 [xlnx + (1-x)ln(1-x)] Ω = 0,6 kcal/mol.
Thermodynamic stability of RuTe2 solid by vapor pressure study
Ali Basu,Shirsat,Mishra,Kerkar,Kumar,Bharadwaj,Das
, p. 140 - 142 (2003)
The vaporization behavior of the intermetallic compound RuTe2(s) was studied in the temperature range of 831-1148 K by the Knudsen effusion technique. As a prerequisite to the study, the nature of the vaporization equilibrium was first obtained. Phase analysis of the partially evaporated sample of RuTe2(s) from thermogravimetric experiment carried out in inert environment showed the TG residue to be a biphasic mixture of Ru(s) and RuTe2(s). This result together with the available thermodynamic information of Te vapor revealed that the compound incongruently volatilize as RuTe2(s)=Ru(s)+Te2(g). The equilibrium vapor pressure of Te2(g) derived from the measurement at the different temperatures could be expressed as ln(p/Pa)(±0.33) = -33231.2/T+33.67 (831 ≤ T/K ≤ 1148). The result of this study is discussed in the light of the reported data on the intermetallic compound.
Absorption Spectra of Tellurium Clusters in Solid Argon
Hassanzadeh, Parviz,Thompson, Craig,Andrews, Lester
, p. 8246 - 8249 (1992)
Tellurium clusters (Te2, Te3, and two structural isomers of Te4) have been prepared by passing tellurium vapor through an argon microwave discharge and condensing the effluent onto a 12 +/- 2 K cold sapphire window.The Te2 diatomic and two isomers of Te4 have also been prepared by passing tellurium vapor through a superheater (800 deg C) followed by condensing with excess argon at 12 +/- 2 K.Absorption bands at 400 and 440 nm were identified as Te2; and the forbidden X2 3Σ-g ground state of Te2 was observed in the infrared spectrum at 1984.3 cm-1.A structured absorption band centered at 665 nm is assigned to Te3, which is in agreement with the resonance Raman excitation profile.Two absorption bands in the near-infrared region (an unstructured band at 760 nm and a structured band centered at 960 nm) were interconverted upon selective photolysis with band-pass filters.These two bands are assigned to structural isomers of Te4 similar to those observed for S4 and Se4.New infrared bands at 243, 232, 224 cm-1 are assigned to the 760-, 665-, and 960-nm absorbing species, respectively, on the basis of their similar photolysis and annealing behaviors.
Thermodynamics of sublimation and crystal chemistry of Tm0.77Te
Petzel, T.,Ludwigs, J.,Greis, O.
, p. 317 - 328 (1989)
The congruent vaporization of solid Tm0.77Te (rhombohedral, with hexagonal lattice parameters a = 430.9 pm, c = 1083.8 pm) was investigated by the Knudsen effusion weight-loss technique over the temperature range 1624 - 1798 K. Using literature data for the enthalpies of dissociation of gaseous TmTe and Te2 and for the free energy functions of gaseous TmTe, Te2, thulium and tellurium, an equation for vaporization to the atoms is given. A vapor pressure equation is provided. Second and third law calculations based on estimated thermodynamic data for Tm0.77Te yielded the standard enthalpies and entropies of reaction. The crystal chemistry and thermochemical properties are discussed.
