On the Zener drag

TL;DR: In this article , annealing a compositionally stepwise Pt-Au film with a homogenous microstructure results in a film with spatial microstructural gradient, exhibiting grains which can be twice as wide in the bulk compared to the outer surfaces.

TL;DR: Researchers develop a method to create ultra-strong, thermally stable bulk nanostructured copper using a multilayer graphene interface, enabling high extensibility through conventional cold-rolling under moderate conditions, achieving exceptional mechanical and electrical properties.

Abstract: Abstract Thermoelectric (TE) materials, capable of directly converting heat into electricity, offer a promising route for sustainable energy recovery. However, practical deployment is limited by the difficulty in simultaneously optimizing electrical and thermal transport properties. In this study, a synergistic microstructure‐composition co‐design strategy for enhancing the performance of PbTe‐based TEs via Na 2 S‐assisted solid‐state synthesis is presented. The thermal decomposition of Na 2 S not only introduces hierarchical porosity but also facilitates initial Na doping, enabling the concurrent optimization of phonon scattering, carrier concentration, and band convergence. The optimized composition, Pb 0.97 Na 0.03 Te‐1.0%Na 2 S, exhibits refined grains, dispersed Na 2 Te nanoprecipitates, and a high density of dislocations, leading to ultralow lattice thermal conductivity (≈0.50 W m −1 K −1 at 750 K) while preserving excellent electrical transport. A peak TE figure of merit zT ≈2.2 at 823 K and a high average zT ≈1.9 across 623–823 K are achieved. To validate the device‐level applicability, single‐leg TE modules are fabricated, achieving a high conversion efficiency of 13.4% at Δ T = 395 K, which is among the best reported for a PbTe‐based system. Furthermore, a unicouple module integrated with n‐type skutterudite reaches a record power density of 2.2 W cm −2 at Δ T = 375 K. This study highlights a scalable pathway for advancing mid‐temperature TE materials and devices through structural and compositional engineering.

TL;DR: In this paper, the detailed movement of a dislocation line through a random array of point obstacles in the glide plane has been examined, using a digital computer, on the basis of the line tension approximation.

TL;DR: In this article, the authors examined the impact of a random distribution of point-like obstacles to the movement of dislocations and proved that a critical applied stress exists; it is determined by a critical value of the fraction of passable obstacles such that the average dislocation segment can keep moving.

TL;DR: In this paper, the ease of motion of a dislocation in a crystal is influenced by changes in lattice parameter and elastic modulus, leading to the production of interface dislocations and suggest a work hardening model for one class of precipitation hardened alloys.