Entropy-stabilized oxides exhibit unusually low lattice thermal conductivity, but the governing mechanisms are not fully understood. We study how lattice distortion controls thermal transport in MgCoNiCuZnO5 (J14). Structural analysis reveals strong, element-specific distortions caused by multication disorder in a single-phase rock-salt lattice. Thermal measurements show highly suppressed phonon transport, consistent with reduced coherent propagation from severe distortion. By varying transition-metal composition, we tune distortion magnitude and modulate thermal conductivity. These results establish elemental lattice distortion as a quantitative descriptor linking structural disorder to thermal transport and guiding thermal property design.
Piezoelectric biomaterials regenerate endogenous electrical signals by transforming mechanical energy into localized electrical stimulation. This study systematically examines the influence of β-tricalcium phosphate (β-TCP) concentration (0–10 wt
Stress–strain relationship is fundamental to understanding mechanical behavior, yet conventional tensile testing provides only bulk-averaged properties and fails to capture local variations. Instrumented indentation testing, particularly with spherical indenter, is often assumed to be capable of uniquely determining stress–strain relationships from a single load–displacement (or P–h) curve. However, our finite element simulations, supported by experimental P–h curves from copper and brass challenge this assumption, demonstrating that different combinations of yield stress and work-hardening exponent can produce indistinguishable indentation responses, highlighting the non-uniqueness. Thus, the quest for obtaining local mechanical properties from spherical indentation measurements continues.
The advancement of 3D printing technology has enabled new approaches for manufacturing composite materials. However, the low crystallinity of polylactic acid (PLA) limits its mechanical and thermal performance. In this study, PLA-based filaments reinforced with 1–3 wt
Classical electromagnetic laws such as Faraday's law are commonly interpreted within a continuum framework in which magnetic flux is treated as a statistically stable observable arising from large ensembles of magnetic dipoles. As magnetic systems approach the isolated nanoparticle limit, this continuum interpretation becomes progressively less robust because the magnetic response is increasingly governed by discrete localized sources rather than coarse-grained ensemble averaging. This work examines the implications of this continuum-to-discrete transition for the classical flux-based formulation of electromagnetic induction. While Maxwell's equations and the superposition principle remain fully valid at all length scales, the conventional interpretation of magnetic flux as a continuum observable loses operational robustness in the discrete-source regime. We show that electromagnetic induction is more naturally represented through the time-dependent vector potential generated directly by localized magnetic sources, providing a source-oriented description that remains fully consistent with classical electrodynamics. The implications for nanoscale magnetometry and isolated magnetic nanoparticles are discussed, identifying the transition from continuum field descriptions to discrete-source representations relevant to emerging nanoscale magnetic systems.Graphical abstract Schematic comparison of electromagnetic induction in the continuum and discrete-source regimes. (a) In a macroscopic magnetic body containing a statistically large ensemble of magnetic dipoles, the magnetic field forms a smooth continuum and produces a well-defined magnetic flux through a conducting loop, giving the classical Faraday relation, (b) An isolated 10-nm Fe3O4 nanoparticle retains a finite localized magnetic dipole moment, but does not sustain a statistically stable macroscopic flux through the loop. In this discrete-source regime, induction is described directly through the time-dependent vector potential, providing a source-oriented formulation consistent with Maxwell electrodynamics.
