Anderson Localization of Phonons in Thermally Superinsulating Graphene Aerogels with Metal-Like Electrical Conductivity.

In the quest to improve energy efficiency and design better thermal insulators, various engineering strategies have been extensively investigated to minimize heat transfer through a material. Yet, the suppression of thermal transport in a material remains elusive because heat can be transferred by multiple energy carriers. Here, the realization of Anderson localization of phonons in a random 3D elastic network of graphene is reported.

The manipulation of natural mineral chalcopyrite CuFeS mechanochemistry: properties and thermoelectric potential.

In this study, the properties of the natural mineral chalcopyrite CuFeS after mechanical activation in a planetary mill were studied. The intensity of mechanical activation was controlled by changing the revolutions of the mill in the range 100-600 min. A series of characterization techniques, such as XRD, SEM, TEM, TA (DTA, TG, and DTG), particle size analysis, and UV-vis spectroscopy was applied and reactivity studies were also performed.

Black Phosphorus: Fundamental Properties and Influence of Impurities Induced by Its Synthesis.

Black phosphorus (BP) has been among the most widely explored materials in recent years because of its exceptional properties. A vapor transport method using tin and iodide as mineralizers was used to synthesize large crystals which can be used for fundamental physical characterization including electrical and heat transport and heat capacity. This method is compared to other reported procedures (high-pressure crystal growth and mercury catalysis) which are broadly used and the most dominant procedures for the obtainment of bulk layered BP.

InSe:Ge-doped InSe van der Waals heterostructure to enhance photogenerated carrier separation for self-powered photoelectrochemical-type photodetectors.

Two-dimensional (2D) van der Waals (vdW) materials with tunable heterostructures and superior optoelectronic properties have opened a new platform for various applications, , field-effect transistors, ultrasensitive photodetectors and photocatalysts. In this work, an InSe/InSe(Ge) (germanium doped InSe) vdW heterostructure is designed to improve the photoresponse performance of sole InSe in a photoelectrochemical (PEC)-type photodetector. Photoelectrochemical measurements demonstrated that this heterostructure has excellent photoresponse characteristics, including a photocurrent density of 9.

Mechanochemistry for Energy Materials: Impact of High-Energy Milling on Chemical, Electric and Thermal Transport Properties of Chalcopyrite CuFeS Nanoparticles.

Chalcopyrite CuFeS , a semiconductor with applications in chemical sector and energy conversion engineering, was synthetized in a planetary mill from elemental precursors. The synthesis is environmentally friendly, waste-free and inexpensive. The synthesized nano-powders were characterized by XRD, SEM, EDX, BET and UV/Vis techniques, tests of chemical reactivity and, namely, thermoelectric performance of sintered ceramics followed.

Modelling and Measurement of Magnetically Soft Nanowire Arrays for Sensor Applications.

Soft magnetic wires and microwires are currently used for the cores of magnetic sensors. Due to their low demagnetization, they contribute to the high sensitivity and the high spatial resolution of fluxgates, Giant Magnetoimpedance (GMI), and inductive sensors. The arrays of nanowires can be prepared by electrodeposition into predefined pores of a nanoporous polycarbonate membrane.

Broadband dielectric spectroscopy of LaSrMnO@TiOcore-shell nanocomposites.

Core-shell composites of ferromagnetic conducting nanoparticles LaSrMnO(LSMO) embedded in an insulating matrix of TiO(LSMO@TiO) have been processed, structurally and magnetically characterized, and their DC magnetoresistivity and complex dielectric response measured and fitted from Hz up to the infrared (IR) range (10Hz). XRD indicates that the TiOshells are amorphous. Modelling of the IR spectra using standard models based on the effective medium approximation has it confirmed and has characterized the effective phonon modes of the LSMO nanoceramics and LSMO@TiOcomposite.

Large-Scale Production of Nanocrystalline Black Phosphorus Ceramics.

Black phosphorus is currently among the most explored two-dimensional (2D) materials. Currently, the synthesis methods are dominantly based on vapor-phase growth of black phosphorus. In this manuscript, we demonstrate large-scale synthesis of black phosphorus by rapid high-pressure transition of red phosphorus.

Thermoelectric properties of the tetrahedrite-tennantite solid solutions CuSbAsS and CuCoSbAsS (0 ≤ x, y ≤ 4).

Tetrahedrites, a class of copper- and sulfur-rich minerals, exhibit inherently very low lattice thermal conductivity and adjustable electronic properties that make them interesting candidates for thermoelectric applications. Here, we investigate the influence of isovalent As substitution on the Sb site on the structural and transport properties (5-700 K) of the two solid solutions Cu12Sb4-xAsxS13 and Cu10Co2Sb4-yAsyS13 (0 ≤ x, y ≤ 4). Electronic band structure calculations predict that As has only a weak influence on the valence bands and hence, on the p-type metallic character of Cu12Sb4S13.

Effects of Tb(3+) dopants in the La1-x Sr x MnO3 bulk and nanoparticle ferromagnets.

Three forms of La,Sr-manganites are synthesized and the role of Tb doping is investigated. First two systems are sol-gel nanoparticles and sintered ceramics of the composition La0.56Tb0.

X-ray characterization, electronic band structure, and thermoelectric properties of the cluster compound Ag2Tl2Mo9Se11.

We report on a detailed investigation of the crystal and electronic band structures and of the transport and thermodynamic properties of the Mo-based cluster compound Ag2Tl2Mo9Se11. This novel structure type crystallizes in the trigonal space group R3̅c and is built of a three-dimensional network of interconnected Mo9Se11 units. Single-crystal X-ray diffraction indicates that the Ag and Tl atoms are distributed in the voids of the cluster framework, both of which show unusually large anisotropic thermal ellipsoids indicative of strong local disorder.