Search arXiv⌕ Search

arXiv · 2610.36619

Comprehensive QM/ML Study of Dislocation Loop Line Segments in α-Zr Part I: Loop Core Geometries, Solute Binding, and Transition Barriers

Abstract

Zr cladding alloys in nuclear reactors are exposed to high neutron fluxes, making irradiation-induced defects and solute segregation central to understanding their in-service behaviour. Dislocation cores involve short-range chemistry and long-range elastic fields, which are difficult to describe simultaneously using conventional atomistic methods. Using a hybrid quantum mechanics/machine learning (QM/ML) framework, this part of work examines prismatic loops in hcp α-Zr. All three loop variants are considered, including faulted and perfect, interstitial- and vacancy-type, and first- and second-order prismatic configurations. Nine possible dislocation line segments are characterised in terms of core geometry, solute binding, glide barriers and faulted-to-perfect transition pathways using QM/ML and newly implemented QM/ML-NEB calculations. Shockley and half-Shockley partials, together with basal and prismatic fault ribbons, are found to govern core stabilisation. Fe and H preferentially bind to faulted segments, whereas Sn and Nb favour perfect segments. Solutes can also drive partial motion, recombination and local unfaulting. These results establish a comprehensive picture of loop microstructure, solute trapping and transition mechanisms in α-Zr.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Junting Zhang, Andrew P. Horsfield, Mark R. Wenman. 2026-10-27. Comprehensive QM/ML Study of Dislocation Loop Line Segments in α-Zr Part I: Loop Core Geometries, Solute Binding, and Transition Barriers. https://arxiv.org/abs/2610.36619

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Beyond Geometry: Hole-Edge Atomic Configuration as a Design Variable in Graphyne Kirigami

Kirigami-inspired cuts are an established route to stretchability in two-dimensional materials. At the nanoscale, however, cut edges are not purely geometric: they comprise discrete atomic configurations that can alter the mechanical response. In graphene, a given cut geometry fixes the edge structure; graphyne, a porous carbon allotrope with an intrinsic band gap, lifts this constraint, as identical cut geometries can yield distinct hole-edge configurations. Using molecular dynamics simulations, we report the first atomistic study of $γ$-graphyne kirigami (GYK), and compared with graphene kirigami. GYK reaches yield strains up to 9.6 times that of pristine $γ$-graphyne, with a response governed by both cut geometry and local hole-edge structure. Removing just two carbon atoms at selected edge sites further raises the yield strain by up to 35%, with little loss of yield stress. These findings identify hole-edge atomic configuration as an additional design parameter, expanding the design space for nanoscale kirigami engineering.

cond-mat.mtrl-sci↗

Learning Multiscale Dynamics of Nanoparticle Self-Assembly

Nanoparticle self-assembly offers a powerful route to programmable functional materials, but its dynamics remain difficult to understand because they arise from multiscale, many-body, and environment-dependent interactions. Liquid-phase transmission electron microscopy (LPTEM) enables real-time observation of these dynamics, yet extracting the underlying physical laws from highly stochastic trajectories remains a significant challenge. Here we develop a physics-informed, time-varying autoregressive framework that learns multiscale self-assembly dynamics directly from LPTEM videos. Continuous Eulerian fields with local density and orientational order are coarse-grained from individual video frames and evolved by a sparse, nearest-neighbor operator optimized over a constrained matrix manifold. This interpretable approach captures long-time large scale phase transitions by tracking operator volatility over time, and short-timescale local evolution and transport rules. Crucially, we extract the underlying partial differential equations, where expected symmetries naturally emerge, enabling the direct inference of fundamental coefficients. Our framework provides a robust, computationally efficient tool for discovering hidden physical mechanisms from observational data, opening a path toward the predictive design of self-assembled nanostructures.

cond-mat.mtrl-sci↗

Spin-Charge Conversion in an Epitaxial Kagome Flat-Band Metal

The formation of topological flat bands near the Fermi level in kagome-structured metals has generated substantial research interest. One key consequence of this electronic structure is the strong anisotropy in charge transport, such as the significantly higher in-plane resistivity relative to the out-of-plane direction. However, the spin transport properties of these flat-band kagome metals are still largely unexplored. In this work, we investigate spin-charge conversion in CoSn, a representative flat-band kagome metal. Scanning tunneling microscopy is employed to image the CoSn surface with atomic resolution, and $dI/dV$ spectroscopy shows clear signatures of the flat bands. Using magneto-optical techniques, we quantify the spin-orbit torque (SOT) in bilayers of ferromagnetic nickel (Ni) and c-plane CoSn thin films. We find a large effective spin Hall angle of $θ_{SH} = 0.484 \pm 0.005$ within the CoSn layers, significantly exceeding the value measured for Pt of $θ_{SH} = 0.0436 \pm 0.0003$ in Ni/Pt bilayers. Density functional theory (DFT) calculations provide a microscopic understanding of the intrinsic spin Hall effect in CoSn, elucidating the sources of Berry curvature in momentum space. These findings establish kagome metals as promising materials for efficient spin-charge conversion and low-power spintronics.

cond-mat.mtrl-sci↗