Thermochemistry of the Ga-Se system

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Atıf İçin Kopyala

İDER M., Pankajavalli R., Zhuang W., Shen J., Anderson T.

ECS Journal of Solid State Science and Technology, cilt.4, sa.5, 2015 (SCI-Expanded)

• Yayın Türü: Makale / Tam Makale
• Cilt numarası: 4 Sayı: 5
• Basım Tarihi: 2015
• Doi Numarası: 10.1149/2.0011507jss
• Dergi Adı: ECS Journal of Solid State Science and Technology
• Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
• Uşak Üniversitesi Adresli: Evet

Özet

Solid state electrochemical cells were employed to obtain standard Gibbs energy of formation of Ga2Se3 as well as the temperature and enthalpy of the α to β-Ga2Se3 transformation in the Ga-Se system. The reversible Emfs of the following solid-state electrochemical cells were measured: Pt, Ga(l), Ga2O3(s)||YSZ||Ga2O3(s), GaSe(s), Liquid1, C, Pt I; Pt, Ga(l), Ga2O3(s)||YSZ||Ga2O3(s), GaSe(s), Ga2Se3(s), C, Pt II; Pt, Ga(l), Ga2O3(s)||YSZ||Ga2O3(s), Ga2Se3(s), Liquid2, C, Pt III. The standard molar Gibbs energy of formation of Ga2Se3, which was calculated by analysis of measured data, is given by: ΔG^of(Ga2Se3, α) ± 1.00(kJ/mol) = -442.65 + 0.11816 T(K) (823-962 K); ΔG^of(Ga2Se3, β) ± 0.48(kJ/mol) = -425.46+0.10086 T(K (986-1100 K). The thermodynamic and phase diagram data in the Ga-Se system were critically assessed. A self consistent set of thermochemistry and phase diagram data was obtained with the help of thermochemical measurements. The liquid phase was modeled by the associated solution model with two associates of GaSe and Ga2Se3. The α-Ga2Se3 phase was described by the sublattice model with two sublattices according to the formula (Ga, Va)2 (Se, Va)3. The other two intermediate phases, GaSe and β-Ga2Se3 were treated as line compounds.