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

Abstract

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 2 Tb(−24.7 ± 1.9); Cu 2 Dy(−24.4 ± 2.3); Cu 2 Ho(−25.0 ± 2.3); Cu 2 Er(−27.0 ± 1.6); Cu 2 Tm(−23.4 ± 2.0). 5:1 composition: Cu 5 Tb(−18.4 ± 2.0); Cu 5 Dy(−15.7 ± 2.2); Cu 5 Ho(−17.3 ± 2.1); Cu 5 Er(−18.4 ± 2.0); Cu 5 Tm(−18.9 ± 2.4); Cu 5 Lu (−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.

First-principles study of constitutional and thermal point defects in B2 PdIn

“…For the purpose of comparison, we also show in Fig. 2 the experimental calorimetry measurements by Bryant and Pratt [35] and Meschel and Kleppa [36]. As shown, the formation enthalpies of B2 PdIn alloys were underestimated in our calculations by w10 kJ/mol.…”

“…The solid and dashed lines correspond to unrelaxed and relaxed formation enthalpies, respectively. Experimental data are from Bryant and Pratt[35] and Meschel and Kleppa[36].…”

Thermochemistry of some binary alloys of Samarium with the noble metals (Cu, Ag, Au) by high temperature direct synthesis calorimetry

“…The Sm compounds we are reporting on in the present communication were not studied previously in this laboratory [1][2][3][4][5][6][7][8][9][10][11][12][13]. Among the Cu-Sm systems, for CuSm and for Cu 2 Sm we had some difficulty obtaining samples for the X-ray diffraction analyses.…”

“…Several investigations of the alloys of copper, silver and gold with transition metals and with some of the lanthanide elements were reported by Fitzner and Kleppa [4][5][6][7][8][9]. Recently, we reported our own study of copper, silver and gold with transition metal elements and with some of the lanthanide elements [10][11][12][13]. These earlier investigations did not include compounds of Samarium because these experiments required special handling and had to be carried out at a somewhat lower temperature.…”

“…Over a period of a number of years, a systematic study of the thermochemistry of the alloys of the noble metals with transition metals and with the lanthanide elements has been pursued in this laboratory [1][2][3][4][5][6][7][8][9][10][11][12][13]. Several investigations of the alloys of copper, silver and gold with transition metals and with some of the lanthanide elements were reported by Fitzner and Kleppa [4][5][6][7][8][9].…”