arXiv subjects

Ohad Levy

Publications and source records attributed to Ohad Levy.

23 records · Page 2Linked to original sources

arXiv2014

A high-throughput ab initio review of platinum-group alloy systems

We report a comprehensive study of the binary systems of the platinum group metals with the transition metals, using high-throughput first-principles calculations. These computations predict stability of new compounds in 38 binary systems where no compounds have been reported in the literature experimentally, and a few dozen of as yet unreported compounds in additional systems. Our calculations also identify stable structures at compound compositions that have been previously reported without detailed structural data and indicate that some experimentally reported compounds may actually be unstable at low temperatures. With these results we construct enhanced structure maps for the binary alloys of platinum group metals. These are much more complete, systematic and predictive than those based on empirical results alone.

cond-mat.mtrl-sci↗

arXiv2013

AFLOW: An automatic framework for high-throughput materials discovery

Recent advances in computational materials science present novel opportunities for structure discovery and optimization, including uncovering of unsuspected compounds and metastable structures, electronic structure, surface, and nano-particle properties. The practical realization of these opportunities requires systematic generation and classification of the relevant computational data by high-throughput methods. In this paper we present Aflow (Automatic Flow), a software framework for high-throughput calculation of crystal structure properties of alloys, intermetallics and inorganic compounds. The Aflow software is available for the scientific community on the website of the materials research consortium, aflowlib.org. Its geometric and electronic structure analysis and manipulation tools are additionally available for online operation at the same website. The combination of automatic methods and user online interfaces provide a powerful tool for efficient quantum computational materials discovery and characterization.

cond-mat.mtrl-sci↗

arXiv2013

Stable ordered structures of binary technetium alloys from first principles

Technetium, element 43, is the only radioactive transition metal. It occurs naturally on earth in only trace amounts. Experimental investigation of its possible compounds is thus inherently difficult and limited. Half of the Tc-transition-metal systems (14 out of 28) are reported to be phase separating or lack experimental data. Using high-throughput first-principles calculations, we present a comprehensive investigation of the binary alloys of technetium with the transition metals. The calculations predict stable, ordered structures in nine of these 14 binary systems. They also predict additional compounds in all nine known compound-forming systems and in two of the five systems reported with disordered \c{hi} or σ phases. These results accentuate the incompleteness of the current knowledge of technetium alloys and should guide experimental studies to obtain accurate structural information on potential compounds, obviating some of the difficulties associated with such work.

cond-mat.mtrl-sci↗

arXiv2010

Structure maps for hcp metals from first principles calculations

The ability to predict the existence and crystal type of ordered structures of materials from their components is a major challenge of current materials research. Empirical methods use experimental data to construct structure maps and make predictions based on clustering of simple physical parameters. Their usefulness depends on the availability of reliable data over the entire parameter space. Recent development of high throughput methods opens the possibility to enhance these empirical structure maps by {\it ab initio} calculations in regions of the parameter space where the experimental evidence is lacking or not well characterized. In this paper we construct enhanced maps for the binary alloys of hcp metals, where the experimental data leaves large regions of poorly characterized systems believed to be phase-separating. In these enhanced maps, the clusters of non-compound forming systems are much smaller than indicated by the empirical results alone.

cond-mat.mtrl-sci↗

arXiv2009

Hafnium binary alloys from experiments and first principles

Despite the increasing importance of hafnium in numerous technological applications, experimental and computational data on its binary alloys is sparse. In particular, data is scant on those binary systems believed to be phase separating. We performed a comprehensive study of 44 hafnium binary systems with alkali metals, alkaline earths, transition metals and metals, using high-throughput first principles calculations. These computations predict novel unsuspected compounds in six binary systems previously believed to be phase separating They also predict a few unreported compounds in additional systems and indicate that some reported compounds may actually be unstable at low temperatures. We report the results for the following systems: AgHf, AlHf, AuHf, BaHf*, BeHf, BiHf, CaHf*, CdHf, CoHf, CrHf, CuHf, FeHf, GaHf, HfHg, HfIn, HfIr, HfK*, HfLa*, HfLi*, HfMg, HfMn, HfMo, HfNa*, HfNb*, HfNi, HfOs, HfPb, HfPd, HfPt, HfRe, HfRh, HfRu, HfSc, HfSn, HfSr*, HfTa*, HfTc, HfTi, HfTl, HfV*, HfW, HfY*, HfZn, and HfZr. (* = systems in which the ab initio method predicts that no compounds are stable).

cond-mat.mtrl-sci↗