First-principles study of the effect of phosphorus on nickel grain boundary

Abstract

Based on first-principles quantum-mechanical calculations, the impurity-dopant effects of phosphorus on Σ5(012) symmetrical tilt grain boundary in nickel have been studied. The calculated binding energy suggests that phosphorus has a strong tendency to segregate to the grain boundary. Phosphorus forms strong and covalent-like bonding with nickel, which is beneficial to the grain boundary cohesion. However, a too high phosphorus content can result in a thin and fragile zone in the grain boundary, due to the repulsion between phosphorus atoms. As the concentration of phosphorus increases, the strength of the grain boundary increases first and then decreases. Obviously, there exists an optimum concentration for phosphorus segregation, which is consistent with observed segregation behaviors of phosphorus in the grain boundary of nickel. This work is very helpful to understand the comprehensive effects of phosphorus.

Mechanically exfoliated black phosphorus as a new saturable absorber for both Q-switching and Mode-locking laser operation

“…Furthermore, long-term stability and the damage threshold remain a critical problem for the applications of BPs towards the high power regime. This is because of the fragile atomic binding force and the strong activity of phosphorus atoms in contrast with carbon atoms [43,44]. In order to overcome these problems, we expect that the introduction of BPs with other structures, such as organic polymer (which can protect the oxidation from the air/water) and optical wave-guide structures (by depositing BPs onto the surface of D-shape fiber in order to increase the light propagation distance through the lateral interaction scheme) might mitigate the drawbacks of optical damage.…”

Uncovering the influence of common nonmetallic impurities on the stability and strength of a Σ5 (310) grain boundary in Cu

“…For example, B has been reported to improve the cohesion at grain boundaries in Cu [11], Mo [17] and Fe [36]. Some studies suggest that impurities can form covalent bonds with the host atoms to strengthen interfacial cohesions while others form isotropic polar bonds that cause interfacial embrittlement [17,18,21]. Geng et al [12] showed that the condition for one impurity to be an enhancer was that the atomic size of the impurity must allow it to fit well into the grain boundaries, being neither too small nor too large.…”

Exfoliated layers of black phosphorus as saturable absorber for ultrafast solid-state laser

“…And if we further increased the pump power, the mode-locking operation became unstable and presented a Q-switching instability. In addition to the thermal-lensing-effect-induced cavity instability from the laser crystal, the thermal instability of phosphorene film caused by the fragile atomic binding force and the strong activity of phosphorus atoms were also possible reasons [29]. Moreover, slight mechanic vibration did not affect the mode-locking operation.…”