Enthalpy of Formation of Gallium-Germanium-Tin Liquid Alloys: Evaluation of the Liquidus Surface of the Phase Diagram from Excess Functions of Mixing

1980 ◽  
Vol 35 (11) ◽  
pp. 1256-1264 ◽  
Author(s):  
M. Fornaris ◽  
Y. M. Muggianu ◽  
M. Gambino ◽  
J. P. Bros
Keyword(s):  
Phase Diagram ◽  
High Temperature ◽  
Enthalpy Of Formation ◽  
Binary Systems ◽  
Liquidus Surface ◽  
Enthalpies Of Formation ◽  
Excess Functions ◽  
Liquid Alloys ◽  
Calvet Calorimeter ◽  
Excess Functions Of Mixing

Abstract With a differential high temperature Calvet calorimeter, the enthalpies of formation of Ga-Ge-Sn liquid alloys have been measured at 703, 798, 895, 1000 and 1230 K in the whole concentration area. The experimental results are compared with those obtained by using an interpolation relation on the basis of the excess functions of mixing of the bordering binary systems. The interpolation relation is used to calculate the partial excess functions and to determine the position of the liquidus surface of the Ga-Ge-Sn phase diagram: the experimental and calculated values agree fairly.

Excess energy–volume and cohesive energy density coefficients for binary systems. Comparison with constant pressure functions

1976 ◽  
Vol 54 (22) ◽  
pp. 3559-3563 ◽  
Author(s):  
Digby D. Macdonald
Keyword(s):  
Energy Density ◽  
Cohesive Energy ◽  
Binary Systems ◽  
Constant Pressure ◽  
Liquid Mixtures ◽  
Excess Energy ◽  
Excess Functions ◽  
Cohesive Energy Density ◽  
Excess Functions Of Mixing

Excess energy–volume and cohesive energy density coefficients have been calculated for the hexane + perfluoro-hexane, water + DMSO, water + tert-butanol, water + methanol, water + acetonitrile, and methanol + DMSO Systems. These parameters are compared with other constant pressure excess functions of mixing for these binary systems, and it is proposed that they represent additional criteria for the classification of liquid mixtures.

Enthalpies of formation of LaBO3perovskites (B = Al, Ga, Sc, and In)

2003 ◽  
Vol 18 (10) ◽  
pp. 2501-2508 ◽  
Author(s):  
Jihong Cheng ◽  
Alexandra Navrotsky
Keyword(s):  
High Temperature ◽  
Enthalpy Of Formation ◽  
Solution Calorimetry ◽  
Tolerance Factor ◽  
Enthalpies Of Formation ◽  
Oxide Melt ◽  
High Temperature Oxide ◽  
Temperature Oxide ◽  
First Time ◽  
The Enthalpy Of Formation

Enthalpies of formation from constituent oxides and elements at 298 K were determined by high-temperature oxide melt solution calorimetry for a group of technologically important perovskites LaBO3(B = La, Ga, Sc, and In). Enthalpies of formation from oxides of LaAlO3and LaGaO3are −69.61 ± 3.23 kJ/mol and −52.39 ± 1.99 kJ/mol, respectively. The data were consistent with literature values obtained using other methods. The enthalpies of formation of LaScO3and LaInO3from oxides were reported for the first time as −38.64 ± 2.30 kJ/mol and −23.99 ± 2.31 kJ/mol, respectively. As seen for other perovskites, as the tolerance factor deviates more from unity (in the order Al, Ga, Sc, In), the enthalpy of formation from oxides becomes less exothermic, indicating a less stable structure with respect to the constituent oxides.

Energetics of Manganese Oxides

1995 ◽  
Vol 398 ◽  
Author(s):  
S. Fritsch ◽  
A. Navrotsky
Keyword(s):  
Phase Diagram ◽  
High Temperature ◽  
Enthalpy Of Formation ◽  
Manganese Oxides ◽  
Temperature Drop ◽  
Solution Calorimetry ◽  
Drop Calorimetry ◽  
Thermodynamic Cycles

ABSTRACTThe energetics of some manganese oxides : pyrolusite ΜnO2, bixbyite Μn2O3, hausmannite Μn3O4 and manganosite MnO were studied by transposed temperature drop calorimetry and high temperature drop solution calorimetry in molten 2PbOB2O3 at 977 K. The enthalpies of oxidation at 298 K in the Mn-O system, determined by appropriate thermodynamic cycles, are (in kJ/mol O2) : −441.4 ± 5.8 for the reaction 6 MnO + O2 -> 2 Mn3O4, −201.8 ± 8.7 for 4 Mn3O4 + O2 -> 6 Mn2O3 and −162.1 ± 7.2 for 2 Mn2O3 + O2 -> 4 ΜnO2 These values agree very well with previous data obtained by equilibrium ρθ2 measurements and indicate that direct calorimetrie measurements are well suited to obtain reliable enthalpy of formation data for oxides containing manganese in the 2+, 3+ and 4+ states. The phase diagram of the Mn-O system was calculated using these new values of enthalpies.

scholarly journals Calorimetric measurements of the Ca-Li liquid alloys

2017 ◽  
Vol 53 (3) ◽  
pp. 203-208
Author(s):  
A. Dębski ◽  
G. Garzeł ◽  
W. Zakulski ◽  
W. Gąsior
Keyword(s):  
Thermal Analysis ◽  
Phase Diagram ◽  
High Temperature ◽  
Copper Content ◽  
Ternary Phase ◽  
Ternary Phase Diagram ◽  
Experimental Information ◽  
Liquid Alloys ◽  
Calorimetric Measurements ◽  
High Copper Content

The ternary Cu-Al-Sn phase diagram is the base for several important types of alloys, with relevant industrial interest and applications. The knowledge of the melting/solidification alloys characteristics are determinant for their preparation and properties control. However, there is a lack of experimental information on the ternary phase diagram, at high temperature. In this work, several alloys, with high copper content and additions of Al, up to 10%, and Sn, up to 14% (in wt%), were studied by thermal analysis and by isothermal phase equilibria determination. The alloys liquidus and solidus lines and the binary ? + ? phase field, at 800 ?C, are presented for the studied range of compositions.

Enthalpy of Formation of Rare-earth Silicates Y2SiO5 and Yb2SiO5 and N-containing Silicate Y10(SiO4)6N2

1999 ◽  
Vol 14 (4) ◽  
pp. 1181-1185 ◽  
Author(s):  
Jian-Jie Liang ◽  
Alexandra Navrotsky ◽  
Thomas Ludwig ◽  
Hans J. Seifert ◽  
Fritz Aldinger
Keyword(s):  
Rare Earth ◽  
High Temperature ◽  
Enthalpy Of Formation ◽  
Temperature Drop ◽  
Solution Calorimetry ◽  
Enthalpies Of Formation ◽  
Binary Oxides ◽  
Standard Enthalpies Of Formation ◽  
Oxygen Gas ◽  
The Enthalpy Of Formation

The enthalpies of formation of two rare-earth silicates (Y2SiO5 and Yb2SiO5) and a N-containing rare-earth silicate Y10(SiO4)6N2 have been determined using high-temperature drop solution calorimetry. Alkali borate (52 wt% LiBO2·48 wt% NaBO2) solvent was used at 800 °C, and oxygen gas was bubbled through the melt. The nitrogen-containing silicate was oxidized during dissolution. The standard enthalpies of formation are for Y2SiO5, Yb2SiO5, and Y10(SiO4)6N2, respectively, –22868.54 ± 5.34, –22774.75 ± 8.21, and –14145.20 ± 16.48 kJ/mol from elements, and –52.53 ± 4.83, –49.45 6 ± 8.35, and –94.53 ± 11.66 kJ/mol from oxides (Y2O3 or Yb2O3, SiO2) and nitride (Si3N4). The silicates and N-containing silicate are energetically stable with respect to binary oxides and Si3N4, but the N-containing silicate may be metastable with respect to assemblages containing Y2SiO5, Si3N4, and SiO2. A linear relationship was found between the enthalpy of formation of a series of M2SiO5 silicates from binary oxides and the ionic potential (z/r) of the metal cation.

Enthalpy of formation of liquid alloys Bi + Cd + Ga + Zn, Bi + Cd + Ga + In + Zn, Ga + In + Pb + Zn and Cd + Ga + In + Pb + Zn

1998 ◽  
Vol 95 (10) ◽  
pp. 2267-2279 ◽  
Author(s):  
R. Ouédraogo ◽  
T. S. Kabré ◽  
M. Gambino ◽  
J. P. Bros
Keyword(s):  
Enthalpy Of Formation ◽  
Liquid Alloys

MAGNETIC PROPERTIES OF PSEUDO-BINARY Mn1−xFexSn2 ALLOYS

1993 ◽  
Vol 07 (01n03) ◽  
pp. 867-870 ◽  
Author(s):  
H. SHIRAISHI ◽  
T. HORI ◽  
Y. YAMAGUCHI ◽  
S. FUNAHASHI ◽  
K. KANEMATSU
Keyword(s):  
Field Theory ◽  
Phase Diagram ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
High Temperature ◽  
Magnetic Structure ◽  
Magnetic Phase ◽  
Magnetic Phase Diagram ◽  
Molecular Field ◽  
Magnetic Phases

The magnetic susceptibility measurements have been made on antiferromagnetic compounds Mn1–xFexSn2 and the magnetic phase diagram was illustrated. The high temperature magnetic phases I and III, major phases, were analyzed on the basis of molecular field theory and explained the change of magnetic structure I⇌III occured at x≈0.8.

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