The Binary Phase Diagram Naphthalene-C60

ABSTRACTMolten naphthalene has considerable solubility for C60 (∼5 10−3 in mole fraction) making it a potential solvent for fullerenes; the phase diagram is therefore important. It was also of interest to study whether C60 displays the same anomalous solubility behavior in naphthalene as in hexane, CS2, and toluene, where the solubility increases with temperature up to a maximum near room temperature and decreases subsequently.The naphthalene-C60 eutectic temperature was determined by DSC; the solubility of C60 in the liquid solution up to ∼180 °C was derived by UV spectrophotometry and found to decrease monotonically with increasing temperature from a mole fraction of 5 · 10−3 at the eutectic (∼79.5 °C) to 1.5 · 10−3 at 165 °C; thus, it shows a higher-temperature C60 solubility decrease (with increasing temperature) analogous to the other solutions, while a potential lowertemperature solubility increase (with increasing temperature) is masked by the eutectic. A binary phase diagram based on these data is proposed.

Download Full-text

THERMODYNAMIC STUDY OF BINARY ALLOY SYSTEM (Co–Cr) USING CALPHAD METHOD

Surface Review and Letters ◽

10.1142/s0218625x1850049x ◽

2018 ◽

Vol 25 (02) ◽

pp. 1850049 ◽

Cited By ~ 4

Author(s):

WASEEM ULLAH SHAH ◽

SYED MEHMOOD SHAH ◽

MATIULLAH KHAN ◽

DIL FARAZ KHAN ◽

ATHANASIOS G. MAMALIS ◽

...

Keyword(s):

Phase Diagram ◽

Binary Phase Diagram ◽

Elevated Temperatures ◽

Alloy System ◽

Miscibility Gap ◽

Energy Curve ◽

Binary Phase ◽

Binary Alloy System ◽

Cr System ◽

Increasing Temperature

This paper reports the thermodynamic analysis of (Co–Cr) system using THERMO-calc package (basis for CALPHAD) and PBIN database. Calculations involve binary phase diagram, Gibb’s energy curve and activity curve at three different elevated temperatures 2125[Formula: see text]K, 2150[Formula: see text]K and 2175[Formula: see text]K. Induced miscibility gap is observed at particular concentration. Binary phase diagram shows variation in phases in prescribed alloy with increasing temperature and mole fraction concentration of [Formula: see text]. The total Gibbs energy decreases with increasing temperature showing the stability of Co–Cr system. Activity showed thorough fluctuation resulting in negative deviation from Raoult’s law ideal curve.

Download Full-text

Crystal structures of η′′-Cu3+xSi and η′′′-Cu3+xSi

Acta Crystallographica Section B Structural Science Crystal Engineering and Materials ◽

10.1107/s2052520617006163 ◽

2017 ◽

Vol 73 (4) ◽

pp. 767-774 ◽

Cited By ~ 1

Author(s):

Cinthia Antunes Corrêa ◽

Olivier Perez ◽

Jaromír Kopeček ◽

Petr Brázda ◽

Mariana Klementová ◽

...

Keyword(s):

Phase Diagram ◽

Low Temperature ◽

Crystal Structures ◽

Structure Analysis ◽

Temperature Region ◽

Binary Phase Diagram ◽

Structure Model ◽

Binary Phase ◽

Modulated Phases ◽

Increasing Temperature

The binary phase diagram of Cu–Si is unexpectedly complex in the vicinity of Cu3+xSi. The low-temperature region contains three closely related incommensurately modulated phases denoted, in order of increasing temperature of stability, η′′′, η′′ and η′. The structure analysis of η′ has been reported previously [Palatinuset al. (2011).Inorg. Chem.50, 3743]. Here the structure model for the phases η′′ and η′′′ is reported. The structures could be solved in superspace, but no superspace structure model could be constructed due to the complexity of the modulation functions. Therefore, the structures were described in a supercell approximation, which involved a 4 × 4 × 3 supercell for the η′′ phase and a 14 × 14 × 3 supercell for the η′′′ phase. Both structures are very similar and differ only by a subtle symmetry lowering from η′′ to η′′′. A comparison of the structure models of η′′ and η′′′ with the reported structure of η′ suggests that the reported structure model of η′ contains an incorrect assignment of atomic types.

Download Full-text