A Molecular Dynamics Study of Ag-Ni Nanometric Multilayers: Thermal Behavior and Stability.

Nanometric multilayers composed of immiscible Ag and Ni metals were investigated by means of molecular dynamics simulations. The semi-coherent interface between Ag and Ni was examined at low temperatures by analyzing in-plane strain and defect formation. The relaxation of the interface under annealing conditions was also considered.

Atomistic Simulations of the Crystalline-to-Amorphous Transformation of γ-AlO Nanoparticles: Delicate Interplay between Lattice Distortions, Stresses, and Space Charges.

The size-dependent phase stability of γ-AlO was studied by large-scale molecular dynamics simulations over a wide temperature range from 300 to 900 K. For the γ-AlO crystal, a bulk transformation to α-AlO by an FCC-to-HCP transition of the O sublattice is still kinetically hindered at 900 K. However, local distortions of the FCC O-sublattice by the formation of quasi-octahedral Al local coordination spheres become thermally activated, as driven by the partial covalency of the Al-O bond.

Atomistic Assessment of Melting Point Depression and Enhanced Interfacial Diffusion of Cu in Confinement with AlN.

The continuing trend in heterogeneous integration (i.e., miniaturization and diversification of devices and components) requires a fundamental understanding of the phase stability and diffusivity of nanoconfined metals in functional nanoarchitectures, such as nanomultilayers (NMLs).

Embracing the Chaos: Alloying Adds Stochasticity to Twin Embryo Growth.

High-throughput atomistic simulations reveal the unique effect of solute atoms on twin variant selection in Mg-Al alloys. Twin embryo growth first undergoes a stochastic incubation stage when embryos choose which twin variant to adopt, and then a deterministic growth stage when embryos expand without changing the selected twin variant. An increase in Al composition promotes the stochastic incubation behavior on the atomic level due to nucleation and pinning of interfacial disconnections.

Ultrahigh Energy Absorption Multifunctional Spinodal Nanoarchitectures.

Nanolattices are promoted as next-generation multifunctional high-performance materials, but their mechanical response is limited to extreme strength yet brittleness, or extreme deformability but low strength and stiffness. Ideal impact protection systems require high-stress plateaus over long deformation ranges to maximize energy absorption. Here, glassy carbon nanospinodals, i.

Linear Complexions: Metastable Phase Formation and Coexistence at Dislocations.

The unique three-phase coexistence of metastable B2-FeNi with stable L1_{0}-FeNi and L1_{2}-FeNi_{3} is discovered near edge dislocations in body-centered cubic Fe-Ni alloys using atomistic simulations. Stable nanoscale precipitate arrays, formed along the compression side of dislocation lines and defined as linear complexions, were observed for a wide range of compositions and temperatures. By analyzing the thermodynamics associated with these phase transitions, we are able to explain the metastable phase formation and coexistence, in the process defining new research avenues for theoretical and experimental investigations.