Ab initio molecular dynamics simulation of the surface composition of Co 54 Ta 11 B 35 metallic glasses

Review on Quantum Mechanically Guided Design of Ultra-Strong Metallic Glasses

“…Our ab initio approach starts with a cubic supercell containing in the order of 115 atoms (Hostert et al, 2011), which is in line with the typical size of a supercell for glassy structures found in literature (Hui et al, 2008b;Fang et al, 2009;Fujita et al, 2009;Hirata et al, 2011;Tian et al, 2011;Galván-Colín et al, 2015;Zhang et al, 2015;Huang et al, 2016) and represents the lower limit required for physically significant models (Holmström et al, 2010). This cell is then annealed at an extremely high temperature such as 4000 K for 400 fs (Hostert et al, 2011), then quenched to 0 K (Hostert et al, 2011;Schnabel et al, 2015) or room temperature (Zhang et al, 2015) with infinite quenching rate. At the final temperature, the atomic structure is equilibrated (Hostert et al, 2011;Zhang et al, 2015;Yu et al, 2016).…”

“…To evaluate the relevance of the ab initio structures, the topology of the simulated samples is compared to the topology of the experimental samples. If the overall topologies are consistent, the structural analysis of the prediction often yields more detail than experimental studies (Qin et al, 2007;Ganesh and Widom, 2008;Hui et al, 2008b;Fang et al, 2009;Fujita et al, 2009;Hui et al, 2009;Hirata et al, 2011;Tian et al, 2011;Durandurdu, 2012;Wu et al, 2012;Zhang et al, 2015;Huang et al, 2016;Hunca et al, 2016;Yu et al, 2016). However, the electronic structure of metallic glasses is analyzed in only few studies (Hostert et al, 2011;Hunca et al, 2016;Schnabel et al, 2016aSchnabel et al, , 2017.…”

“…As the selection of reliable interatomic potentials for classical, semi-empirical potential molecular dynamics (MD) is challenging due to the anharmonicity in metallic glasses (Lambson et al, 1986;Crespo et al, 2016;Aitken et al, 2018), density functional theorybased ab initio MD has been used to calculate the properties of a vast number of materials as it does not require the input of interatomic potentials while being able to cover many-body interactions. By ab initio modeling, an in-depth analysis of the structure-property relationship of metallic glasses is possible that is otherwise challenging to probe only by experimental means, including parameters such as the partial pair correlations (Qin et al, 2007;Ganesh and Widom, 2008;Hui et al, 2008bHui et al, , 2009Fang et al, 2009;Tian et al, 2011;Zhang et al, 2015;Hunca et al, 2016;Yu et al, 2016), coordination polyhedra (Ganesh and Widom, 2008;Fang et al, 2009;Fujita et al, 2009;Hui et al, 2009;Hirata et al, 2011;Tian et al, 2011;Durandurdu, 2012;Wu et al, 2012;Zhang et al, 2015;Huang et al, 2016;Yu et al, 2016) and bonding Hunca et al, 2016). However, modeling the dynamics involved in relaxation and rejuvenation phenomena is out of reach for ab initio molecular dynamics due to the limitations of time steps and cell size as discussed below.…”

“…This cell is then annealed at an extremely high temperature such as 4000 K for 400 fs (Hostert et al, 2011), then quenched to 0 K (Hostert et al, 2011;Schnabel et al, 2015) or room temperature (Zhang et al, 2015) with infinite quenching rate. At the final temperature, the atomic structure is equilibrated (Hostert et al, 2011;Zhang et al, 2015;Yu et al, 2016). The heating -quenching -equilibration cycle is done once (Fang et al, 2009;Fujita et al, 2009;Galván-Colín et al, 2015;Zhang et al, 2015) or repeatedly until the volume is self-consistent (Hostert et al, 2011).…”

“…At the final temperature, the atomic structure is equilibrated (Hostert et al, 2011;Zhang et al, 2015;Yu et al, 2016). The heating -quenching -equilibration cycle is done once (Fang et al, 2009;Fujita et al, 2009;Galván-Colín et al, 2015;Zhang et al, 2015) or repeatedly until the volume is self-consistent (Hostert et al, 2011).…”