Characterization of platinum nitride from first-principles calculations

Date
2009
Authors
Yıldız, A.
Akıncı, Ü.
Gülseren, O.
Sökmen, İ.
Advisor
Instructor
Source Title
Journal of Physics: Condensed Matter
Print ISSN
1361-648X
Electronic ISSN
Publisher
Institute of Physics Publishing
Volume
21
Issue
48
Pages
1 - 8
Language
English
Type
Article
Journal Title
Journal ISSN
Volume Title
Abstract

We have performed a systematic study of the ground state properties of the zinc-blende, rock-salt, tetragonal, cuprite, fluorite and pyrite phases of platinum nitride by using the plane wave pseudopotential calculations within the density functional theory. The equilibrium structural parameters and bulk moduli are computed within both the local density approximation (LDA) and generalized gradient approximation (GGA). The comparison of the equation of state (EOS) calculated within the LDA for the pyrite structure with the experimental results demonstrates an excellent agreement, hence the use of the LDA rather than the GGA is essential. Complete sets of elastic moduli are presented for cubic forms. The analysis of the results reveal that the pyrite phase with PtN2 stoichiometry leads to the formation of a hard material with the shear modulus G = 206 GPa. The electronic structure of pyrite PtN2 is given, which shows a narrow indirect gap. The vibrational properties of platinum nitride are investigated in detail from lattice dynamical calculations. The calculations show that fluorite and pyrite structures are dynamically stable as well. However, the calculated vibrational modes of pyrite PtN2 do not show complete agreement with experimental Raman frequencies.

Course
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Book Title
Keywords
Bulk modulus, Complete sets, Cubic form, Dynamical calculations, Equation of state, First-principles calculation, Generalized gradient approximations, Ground state properties, Hard material, Plane wave, Platinum nitride, Pseudopotential calculation, Raman frequencies, Rock salt, Shear modulus, Structural parameter, Systematic study, Vibrational modes, Vibrational properties, Zinc-blende, Density functional theory, Electronic structure, Equations of state, Fluorspar, Nitrides, Platinum, Pyrites, Stoichiometry, Zinc, Elastic moduli
Citation
Published Version (Please cite this version)