Thermochemistry of some binary alloys of copper with the lanthanide metals by high-temperature direct synthesis calorimetry

• Published in: Journal of alloys and compounds 2005-02, Vol.388 (1), p.91-97
• Main Authors: Meschel, S.V., Kleppa, O.J.
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Copper; Enthalpy; Exact sciences and technology; Lanthanide; Physics; Thermal properties of condensed matter; Thermodynamics
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2004.08.062

The standard enthalpies of formation of some lanthanide–copper compounds have been measured by high-temperature direct synthesis calorimetry at 1373 ± 2 K. The following results (in kJ/mol of atoms) are reported: 2:1 composition: Cu 2Tb(−24.7 ± 1.9); Cu 2Dy(−24.4 ± 2.3); Cu 2Ho(−25.0 ± 2.3); Cu 2Er(−27.0 ± 1.6); Cu 2Tm(−23.4 ± 2.0). 5:1 composition: Cu 5Tb(−18.4 ± 2.0); Cu 5Dy(−15.7 ± 2.2); Cu 5Ho(−17.3 ± 2.1); Cu 5Er(−18.4 ± 2.0); Cu 5Tm(−18.9 ± 2.4); Cu 5Lu(−18.8 ± 1.9). The results are compared with values available in the literature, with the predictions on the basis of the semi-empirical model of Miedema and coworkers and with the values predicted by Gschneider for lanthanide alloys. The results for the Cu alloys are also compared with the recently reported enthalpies of formation of the Ag–LA and Au–LA systems by the present authors.