Atomism in the Aeneid

This book examines the role of philosophical metaphor and allegory in the Aeneid, focusing on tendentious allusions to Lucretian atomism. It argues that Virgil, drawing upon a popular strain of anti-atomist and anti-Epicurean arguments in Greek philosophy, deploys atomic imagery as a symbol of cosmic and political disorder. The first chapter of this study investigates the development of metaphors and analogies in philosophical texts ranging from Aristotle to Cicero that equate atomism with cosmological caprice and instability. The following three chapters track how Virgil applies this interpretation of Epicurean physics to the Aeneid, in which chaotic atomic imagery is associated with various challenges to the poem’s dominant narrative of divine order and Roman power. For Aeneas, the specter of atomic disorder arises at moments of distress and hesitation, while the association of various non-Trojan characters with atomism characterizes them as agents of violent disorder needing to be contained or vanquished. The final chapter summarizes findings, showing how Virgilian allusion to Lucretian physics often conflates poetic, political, and cosmological narratives, blurring the boundaries between their respective modes of discourse and revealing a general preference for hierarchical, teleological models of order.

Enhanced atomic ordering leads to high thermoelectric performance in AgSbTe2

High thermoelectric performance is generally achieved through either electronic structure modulations or phonon scattering enhancements, which often counteract each other. A leap in performance requires innovative strategies that simultaneously optimize electronic and phonon transports. We demonstrate high thermoelectric performance with a near room-temperature figure of merit, ZT ~ 1.5, and a maximum ZT ~ 2.6 at 573 kelvin, by optimizing atomic disorder in cadmium-doped polycrystalline silver antimony telluride (AgSbTe2). Cadmium doping in AgSbTe2 enhances cationic ordering, which simultaneously improves electronic properties by tuning disorder-induced localization of electronic states and reduces lattice thermal conductivity through spontaneous formation of nanoscale (~2 to 4 nanometers) superstructures and coupling of soft vibrations localized within ~1 nanometer around cadmium sites with local strain modulation. The strategy is applicable to most other thermoelectric materials that exhibit inherent atomic disorder.

Enhancing Superconductivity of the Nonmagnetic Quasiskutterudites by Atomic Disorder

We investigated the effect of enhancement of superconducting transition temperature Tc by nonmagnetic atom disorder in the series of filled skutterudite-related compounds (La3M4Sn13, Ca3Rh4Sn13, Y5Rh6Sn18, Lu5Rh6Sn18; M= Co, Ru, Rh), where the atomic disorder is generated by various defects or doping. We have shown that the disorder on the coherence length scale ξ in these nonmagnetic quasiskutterudite superconductors additionally generates a non-homogeneous, high-temperature superconducting phase with Tc⋆>Tc (dilute disorder scenario), while the strong fluctuations of stoichiometry due to increasing doping can rapidly increase the superconducting transition temperature of the sample even to the value of Tc⋆∼2Tc (dense disorder leading to strong inhomogeneity). This phenomenon seems to be characteristic of high-temperature superconductors and superconducting heavy fermions, and recently have received renewed attention. We experimentally documented the stronger lattice stiffening of the inhomogeneous superconducting phase Tc⋆ in respect to the bulk Tc one and proposed a model that explains the Tc⋆>Tc behavior in the series of nonmagnetic skutterudite-related compounds.