A New Approach to the Computer Modeling of Amorphous Nanoporous Structures of Semiconducting and Metallic Materials: A Review

Abstract

We review our approach to the generation of nanoporous materials, both semiconducting and metallic, which leads to the existence of nanopores within the bulk structure. This method, which we have named as the expanding lattice method, is a novel transferable approach which consists first of constructing crystalline supercells with a large number of atoms and a density close to the real value and then lowering the density by increasing the volume. The resulting supercells are subjected to either ab initio or parameterized—Tersoff-based—molecular dynamics processes at various temperatures, all below the corresponding bulk melting points, followed by geometry relaxations. The resulting samples are essentially amorphous and display pores along some of the “crystallographic” directions without the need of incorporating ad hoc semiconducting atomic structural elements such as graphene-like sheets and/or chain-like patterns (reconstructive simulations) or of reproducing the experimental processes (mimetic simulations). We report radial (pair) distribution functions, nanoporous structures of C and Si, and some computational predictions for their vibrational density of states. We present numerical estimates and discuss possible applications of semiconducting materials for hydrogen storage in potential fuel tanks. Nanopore structures for metallic elements like Al and Au also obtained through the expanding lattice method are reported.

Superconductivity in Bismuth. A New Look at an Old Problem

“…As far as we know no other theoretical or computational result has been reported for amorphous bismuth and in what follows we present the vibrational and electronic densities of state obtained for the a-Bi 216 structure that led to a PDF in agreement with experiment. Our accumulated simulational results indicate that the undermelt-quench method is a good approach for the generation of amorphous topologies of a variety of materials, semiconducting or metallic, elemental or alloyed [ 23 , 26 , 27 ]. Without sufficient experimental results for comparison we deposit our confidence in the realistic structures that we have generated using this approach.…”

Modelling and Microstructural Characterization of Sintered Metallic Porous Materials

“…The results can be used to develop the simulation model of a porous material showing its spatial configuration [35]. Further, after the course of studies of metaball modeling has been developed, FEM methods are likely to be used.…”

Computational alternatives to generate amorphous nanoporous structures using ab initio molecular dynamics

“…EL consists of building a crystalline supercell with a given number of atoms and a density which is close to the real material; then the density is diminished by increasing the volume of the cell and proportionally the interatomic distances [6]. The EL technique [5] is shown schematically in Fig.…”