Density functional theory study of phase stability, vibrational, and electronic properties of Mo sub(3)Al sub(2)C

Based on density functional theory the noncentrosymmetric superconductor Mo sub(3)Al sub(2)C in its well-established beta -Mn-type (P4 sub(1)32) crystal structure is investigated. In particular, its thermodynamical and dynamical stabilities are studied by calculating lattice vibrations within the ha...

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Bibliographic Details
Published in:Physical review. B, Condensed matter and materials physics Condensed matter and materials physics, 2012-09, Vol.86 (10)
Main Authors: Reith, D, Blaas-Schenner, C, Podloucky, R
Format: Article
Language:English
Subjects:
Approximation
Carbon
Condensed matter
Crystal structure
Density functional theory
Lattice vacancies
Mathematical analysis
Phase stability
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Summary:Based on density functional theory the noncentrosymmetric superconductor Mo sub(3)Al sub(2)C in its well-established beta -Mn-type (P4 sub(1)32) crystal structure is investigated. In particular, its thermodynamical and dynamical stabilities are studied by calculating lattice vibrations within the harmonic approximation. It is found that the fully stoichiometric compound is dynamically unstable. However, compounds with carbon vacancies (i.e., Mo sub(3) Al sub(2) C sub(1-x)) can be dynamically stabilized for vacancy concentrations x > 0.09. By means of a simple thermodynamical model we estimate x ~ 0.13-0.14 for Mo sub(3) Al sub(2) C sub(1-x) at the experimental preparation temperatures. The influence of the carbon vacancy concentration on the electronic structure is investigated.
ISSN:1098-0121
1550-235X