Molecular Dynamics Calculations of Grain Boundary Mobility in CdTe

Abstract

Molecular dynamics (MD) simulations have been applied to study mobilities of Σ3, Σ7 and Σ11 grain boundaries in CdTe. First, an existing MD approach to drive the motion of grain boundaries in face-centered-cubic and body-centered-cubic crystals was generalized for arbitrary crystals. MD simulations were next performed to calculate grain boundary velocities in CdTe crystals at different temperatures, driving forces, and grain boundary terminations. Here a grain boundary is said to be Te-terminated if its migration encounters sequentially C d · T e − C d · T e … planes, where “·” and “−” represent short and long spacing respectively. Likewise, a grain boundary is said to be Cd-terminated if its migration encounters sequentially T e · C d − T e · C d … planes. Grain boundary mobility laws, suitable for engineering time and length scales, were then obtained by fitting the MD results to Arrhenius equation. These studies indicated that the Σ3 grain boundary has significantly lower mobility than the Σ7 and Σ11 grain boundaries. The Σ7 Te-terminated grain boundary has lower mobility than the Σ7 Cd-terminated grain boundary, and that the Σ11 Cd-terminated grain boundary has lower mobility than the Σ11 Te-terminated grain boundary.

Characterization of Grain Boundary‐Engineered Aluminum–Magnesium Alloys

“…[ 14,21 ] However, the high fraction of Σ7 boundaries across all samples was unexpected as they are highly mobile compared with Σ3 and therefore less likely to be present in the final sputtered material. [ 22 ] In sample C, the prevalence of Σ7 boundaries is tied to increased boundary migration as the high sputtering rate introduced additional thermal energy into the system, leading to higher temperatures [ 23 ] and greater strain in the sputtered material. [ 15,24 ] Specifically, it is expected that sample C had an average deposition temperature over 125 °C higher than samples A and B.…”

Tilt grain boundaries of hexagonal structures: a spectral viewpoint

“…Depending on how the local imperfections are deviated from the bulk structure, they are classified into vacancies, interstitial atoms, or dislocations [10]. Theories and algorithms are then developed to study the morphology, distribution and dynamics of these local structures, including molecular dynamics technique [1,22], Monte Carlo simulation [20,25], continuum phase-field approaches [29,9], and multi-scale methods [19]. When studying GB structures, the relative orientation and displacement, as well as the dividing planes of two grains, are essential variables.…”