Event
Special Materials Seminar: Sanjay V. Khare
Tuesday, September 10, 2013
2:00 p.m.-3:00 p.m.
Room 1302 Chemical and Nuclear Engineering Bldg.
Professor Ray Phaneuf
phaneuf@lps.umd.edu
Searching for Super Hard Cubic Phases of Cubic Transition Metal Nitrides from Ab Initio Computations
Sanjay V. Khare
Associate Professor
Department of Physics and Astronomy
University of Toledo
Experimental synthesis of noble metal nitrides in the last decade has spurred renewed interest in the study of transition metal nitrides [1]. Density functional theory based high-throughput computations can now speed discovery and synthesis of new materials of desired quality, for small primitive unit cell phases. We will demonstrate the efficacy of this approach from a specific example of the process of the structure-determination of platinum nitride. We will then generalize to a systematic study of mechanical and electronic properties of several cubic phases of nitrides of the transition metals, in zincblende, rocksalt, pyrite, fluorite and CsCl structures using ab initio computations. Relationship of elastic constants to mechanical properties, hardness, Debye temperature and melting points will be shown. We will explore candidates for hard coatings. Relationship of elastic properties to electronic density of states, valence electron density and and bonding will be discussed [2].
References
[1]
J. C. Crowhurst, A.F. Goncharov, B. Sadigh, C.L. Evans, P.G. Morrall, J.L. Ferreira, A.J. Nelson, Synthesis and Characterization of the Nitrides of Platinum and Iridium, Science 311 (2006) 1275.
E. Gregoryanz, C. Sanloup, M. Somayazulu, J. Bardo, G. Fiquet, H.-K. Mao, R. Hemley, Synthesis and characterization of a binary noble metal nitride, Nat. Mater. 3, 294 (2004);
[2]
S. K. R. Patil, S. V. Khare, B. R. Tuttle, J. K. Bording, S. Kodambaka, Mechanical stability of possible structures of PtN investigated using first-principles calculations, Phys. Rev. B, 104118, 73 (2006);
S.K.R. Patil, N.S. Mangale, S.V. Khare, S. Marsillac, Super hard cubic phases of period VI transition metal nitrides: First principles investigation, Thin Sol. Films, 517, 824 (2008).
Z. T. Y. Liu, X. Zhou, S. V. Khare, D. Gall, Structural, mechanical and electronic properties of 3d transition metal nitrides in cubic zincblende, rocksalt and cesium chloride structures: a first-principles investigation, Submitted for publication, under peer review.
