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Title: A theoretical study of the thermodynamic properties of YMgX{sub 4} (X=Co, Ni, Cu) compounds

The stability, electronic structures, elastic and thermal properties of the ternary YMgX{sub 4} (X=Co, Ni, Cu) compounds are investigated by first principle calculations in combination with the quasi-harmonic Debye model. The three compounds are predicted to be stable according to the formation enthalpies (ΔH), elastic constants (c{sub ij}) and phonon dispersion models. The elastic constants and polycrystalline elastic moduli reveal the relatively low anisotropy of these compounds. The electronic structures and bonding characters are analyzed by the electron densities of states and difference charge densities in the (110) plane. The comparisons between the phonon density of state and the quasi-harmonic Debye model imply the heat capacities (C{sub v}) and vibrational entropies (S) are close for YMgCo{sub 4} and YMgCu{sub 4}, whereas large deviation for YMgNi{sub 4}. A possible reason is that YMgNi{sub 4} has the slightly strong directional bondings, relative to YMgCo{sub 4} and YMgCu{sub 4}.
Authors:
; ;  [1]
  1. Institute for Applied Physics, University of Science and Technology Beijing, Beijing 100083 (China)
Publication Date:
OSTI Identifier:
22299774
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Advances; Journal Volume: 4; Journal Issue: 9; Other Information: (c) 2014 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ANISOTROPY; CHARGE DENSITY; DENSITY; ELECTRON DENSITY; ELECTRONIC STRUCTURE; ENTROPY; FORMATION HEAT; POLYCRYSTALS; SPECIFIC HEAT; STABILITY