Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8002515 | Journal of Alloys and Compounds | 2013 | 34 Pages |
Abstract
Standard enthalpies of formation at 298 K of selected ternary Co2-based Heusler compounds Co2YZ (Y = Fe, Hf, Mn, Ti, V, Zr; Z = Al, Ga, In, Si, Ge, Sn) were measured by high temperature direct synthesis calorimetry. The measured enthalpies of formation (in kJ/mole of atoms) of the L21 compounds are: Co2FeGa (â25.8 ± 2.6); Co2FeSi (â38.4 ± 2.2); Co2FeGe (â11.6 ± 2.1); Co2MnGa (â30.1 ± 2.3); Co2MnSi (â42.4 ± 1.2); Co2MnGe (â31.6 ± 3.0); Co2MnSn (â15.6 ± 2.8); Co2TiAl (â55.0 ± 3.7); Co2TiGa (â54.2 ± 2.6); Co2TiSi (â61.4 ± 1.7); Co2TiGe (â59.3 ± 3.8); Co2TiSn (â38.4 ± 2.0); Co2VGa (â28.4 ± 1.1) and for the B2 compounds: Co2FeAl (â22.5 ± 2.5), Co2MnAl (â27.6 ± 2.7). Values are compared with those from first principles calculation when available and the extended semi-empirical model of Miedema. Trends in enthalpy of formation with element atomic number are discussed. Lattice parameters of the compounds with L21 structure are determined by X-ray diffraction analysis.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
Ming Yin, Song Chen, Philip Nash,