Phase equilibria of the Gd-Se system

2009

Section: Methodsmentioning

confidence: 99%

High-temperature enthalpy of praseodymium selenides in the homogeneity range bounded by Pr3Se4 and Pr2Se3

Litvinenko

2009

“…The higher enthalpy of melting for Gd 2 Se 3 by comparison with Δ m H° for the isostructural incongruently melting selenides of lanthanum, praseodymium, and neodymium [10] is probably due to the congruent [11] melting of that compound. Figure 1 compares the low-temperature thermal capacities of gadolinium sesquiselenide and sesquisulfide, with o p C for the sesquiselenide higher throughout the temperature range.…”

Section: Research Methods and Resultsmentioning

confidence: 99%

“…Published data give the melting point of Gd 2 Se 3 as 2023 ± 25 K [1] or 1943 K [11]. The thermal capacity in the liquid state is 262.81 J ⋅ mole −1 ⋅ K −1 .…”

Section: Research Methods and Resultsmentioning

confidence: 99%

The thermal capacity and enthalpy of gadolinium sesquiselenide over a wide temperature range

Gorbachuk

2006

536.631′722:546.662′23 Measurements have been made on the thermal capacity of γ-Gd 2 Se 3 at 58.88-298.34 K. Values have been obtained for the thermal capacity, entropy, reduced Gibbs energy, and enthalpy under standard conditions:The enthalpy of Gd 2 Se 3 has been measured and the major thermodynamic functions have been calculated for the solid and liquid states over the temperature range 450-2300 K. The temperature dependence of the enthalpy in the ranges 300-1800 K and 2000-2300 K are represented: H°(T) − H°(298.15 K) = = 1.1949 ⋅ 10 −2 ⋅ T 2 + 122.38 ⋅ T + 347402 ⋅ T −1 − 38716 and H°(T) − H°(298.15 K) = 262.81 ⋅ T − − 196047, respectively. The calculated temperature, enthalpy, and entropy of melting for Gd 2 Se 3 are: T m = 1925 ± 40 K, Δ m H°(Gd 2 Se 3 ) = 68.5 kJ ⋅ mole −1 , Δ m S°(Gd 2 Se 3 ) = 35.6 J ⋅ mole −1 ⋅ K −1 .

“…Lanthanum selenides were synthesized in a capsule in several stages from highly pure elements (Se of OSCh22-4 grade, La with 99.9% purity) [13]. According to x-ray diffraction and chemical analyses, the samples were stoichiometric and contained no other phases.…”

Section: Calorimetric Experimentsmentioning

confidence: 99%

Thermodynamic properties and high-temperature behavior of lanthanum selenides La3Se4-La2Se3

Litvinenko

2008