Large Improvement of Thermoelectric Performance by Magnetism in Co-Based Full-Heusler Alloys.

Full-Heusler alloys (fHAs) exhibit high mechanical strength with earth-abundant elements, but their metallic properties tend to display small electron diffusion thermopower, limiting potential applications as excellent thermoelectric (TE) materials. Here, it is demonstrated that the Co-based fHAs Co XAl (X = Ti, V, Nb) exhibit relatively high thermoelectric performance due to spin and charge coupling. Thermopower contributions from different magnetic mechanisms, including spin fluctuation and magnon drag are extracted.

Symmetry-Guaranteed High Carrier Mobility in Quasi-2D Thermoelectric Semiconductors.

Quasi-2D semiconductors have garnered immense research interest for next-generation electronics and thermoelectrics due to their unique structural, mechanical, and transport properties. However, most quasi-2D semiconductors experimentally synthesized so far have relatively low carrier mobility, preventing the achievement of exceptional power output. To break through this obstacle, a route is proposed based on the crystal symmetry arguments to facilitate the charge transport of quasi-2D semiconductors, in which the horizontal mirror symmetry is found to vanish the electron-phonon coupling strength mediated by phonons with purely out-of-plane vibrational vectors.

An ingroup disadvantage in recognizing micro-expressions.

Micro-expression is a fleeting facial expression of emotion that usually occurs in high-stake situations and reveals the true emotion that a person tries to conceal. Due to its unique nature, recognizing micro-expression has great applications for fields like law enforcement, medical treatment, and national security. However, the psychological mechanism of micro-expression recognition is still poorly understood.

Anomalous Thermoelectric Performance in Asymmetric Dirac Semimetal BaAgBi.

Multiple-band degeneracy has been widely recognized to be beneficial for high thermoelectric performance. Here, we discover that the p-type Dirac bands with lower degeneracy synergistically produce a higher Seebeck coefficient and electrical conductivity in topological semimetal BaAgBi. The anomalous transport phenomenon intrinsically originated from the asymmetric electronic structures: (i) complete p-type Dirac bands near the Fermi level facilitate high and strong energy-dependent hole relaxation time; (ii) the presence of additional parabolic conduction valleys allows for a large density of states to accept scattered electrons, leading to an enlarged hole-electron relaxation time ratio and, thus, weakened bipolar effect.

Exploring Low Power and Ultrafast Memristor on p-Type van der Waals SnS.

Memristor devices that exhibit high integration density, fast speed, and low power consumption are candidates for neuromorphic devices. Here, we demonstrate a filament-based memristor using p-type SnS as the resistive switching material, exhibiting superlative metrics such as a switching voltage ∼0.2 V, a switching speed faster than 1.

Atomic-Scale Visualization and Quantification of Configurational Entropy in Relation to Thermal Conductivity: A Proof-of-Principle Study in -GeSbTe.

It remains a daunting task to quantify the configurational entropy of a material from atom-revolved electron microscopy images and correlate the results with the material's lattice thermal conductivity, which strides across statics, dynamics, and thermal transport of crystal lattice over orders of magnitudes in length and time. Here, a proof-of-principle study of atomic-scale visualization and quantification of configurational entropy in relation to thermal conductivity in single crystalline trigonal GeSbTe (aka -GeSbTe) with native atomic site disorder is reported. A concerted effort of large -GeSbTe single crystal growth, in-lab developed analysis procedure of atomic column intensity, the visualization and quantification of configurational entropy including corresponding modulation, and thermal transport measurements enable an entropic "bottom-up" perspective to the lattice thermal conductivity of -GeSbTe.

Dynamic Epitaxial Crystallization of SnSe on the Oxidized SnSe Surface and Its Atomistic Mechanisms.

Surface oxidation of SnSe sharply reduces its thermoelectric properties though the bulk single-crystalline materials of SnSe claim the record high zT values. Investigation on the oxidation behaviors of SnSe together with the subsequent phase transition and element migration is fundamentally important to maintaining the ultrahigh zT values, with a potential for further improvement. In this work, we disclose the dynamic epitaxial crystallization of SnSe on the amorphous surface of partially oxidized SnSe crystals and the corresponding atomistic mechanisms transmission electron microscopy (TEM).

Synergistic Strategy to Enhance the Thermoelectric Properties of CoSbSSe Compounds via Solid Solution.

High thermal conductivity of CoSbS-based limited its own prospect application in thermoelectric energy conversion. Solid solution is an effective approach to optimize the performance of thermoelectric materials with high lattice thermal conductivity because of the enhanced phonons scattering from disorder atoms. In this paper, we have synthesized and measured the thermoelectric properties of solid solution CoSbSSe (x = 0, 0.

Raising the Thermoelectric Performance of Fe3CoSb12 Skutterudites via Nd Filling and In-Situ Nanostructuring.

p-type skutterudites NdxFe3CoSb12 with x equaling 0.8, 0.85, 0.