Synthesis and electrical properties of Bi₂Te₃ - based thermoelectric materials doped with Er, Tm, Yb, and Lu

Nanopowders of Bi₂Te₃ and R₀.₁Bi₁.₉Te₃ (where R = Er, Tm, Yb, Lu) are obtained by microwave solvothermal synthesis. The powder-like materials are compacted by cold isostatic compression followed by annealing in argon. The influence of the doping agent on the structure and characteristics of the derived materials are investigate

Evolution of the phase composition of ZrB₂-35MoSi₂-15Al composite coating at annealing

In this article, new composite coatings ZrB₂-35MoSi₂-15Al were deposited on the surface of a carbon-carbon composite using a multi-chamber detonation accelerator. The evolution of the phase composition of ZrB₂-35MoSi₂-15Al coatings was analyzed with differential scanning calorimeter (DSC) and X-ray diffractometry (in situ HT-XRD) at temperatures from room temperature (~ 25°C) to 1400°C (normal atmosphere and pressure

Cobalt-based ZIF-68 and ZIF-69 as the precursors of non-platinum electrocatalysts for oxygen reduction

We report the microwave-assisted synthesis of Co-based ZIF-68 and ZIF-69 zeolitic imidazolate frameworks, which were enriched with iron(ii) acetate and 1,10-phenanthroline and then pyrolyzed to form heterogeneous catalysts. The materials demonstrated high activity in oxygen reduction and suitability as Pt-free catalysts for low-temperature fuel cell

Influence of nitriding parameters in radio-frequency inductive discharge plasma on the structural-phase state and properties of H12MF steel

The influence of technological parameters of plasma nitriding on the structural-phase state and mechanical properties of H12MF steel has been investigated in this work. The possibility of improving the corrosion resistance of the reported material was demonstrated by changing the content of nitride phases (Fe3N, Fe4N, CrN) in the surface layer, depending on the nitriding mod

Effect of heat treatment of the alumina powder on the microstructure and properties of coatings

The alumina powder was treated at a high temperature (1000°C). Dense (porosity of less than 2%), solid (1280 ± 30 HV0.3) and wear-resistant coatings based on heat-treated alumina powder were obtained by a multi-chamber detonation sprayer on the steel substrate. The microstructure, microhardness and the wear resistance of the alumina coatings were investigate

Influence of formation conditions, subsequent annealing and ion irradiation on the properties of nanostructured coatings based on amorphous carbon with gold, silver and nitrogen additives

Nanostructured coatings based on amorphous carbon and carbon-doped with gold, silver, and nitrogen were obtained by the pulsed vacuum-arc method. Carbon coatings have been annealed in a vacuum as well as treated with argon ion

Synthesis and properties of thermoelectric nanomaterial AgInSe₂ with a chalcopyrite structure

The aim of this study is to develop a simple, efficient, and scalable method for the preparation of nanoparticles of complex chalcogenides using the example of the AgInSe₂ designed to obtain bulk thermoelectric material

Synthesis and electric transportation properties of high-entropy oxides based on cerium oxide

CeGdRLaPrO2-δ (where R: La, Y and Dy) rare-earth high-entropy oxides (HEOx) with the Ia-3 (206) structure were obtained. The structural, microstructural and transport properties of the compounds were studied. All samples exhibiting good homogeneity and electrical conductivity typical of materials for the manufacture of solid electrolyte

Microstructure and thermoelectric properties of the medium-entropy BiSbTe₁.₅Se₁.₅ and PbSnTeSe compounds prepared by reactive spark plasma sintering

Reactive spark plasma sintering (RSPS) is used to obtain single-phase samples of medium-entropy BiSbTe₁.₅Se₁.₅ compounds (low-temperature thermoelectric electronic type of conductivity) and PbSnTeSe (medium temperature hole-type thermoelectric conductor) from a mixture of powders of the corresponding elemental metals. The obtained samples are polycrystalline with lamellar grains with the average size of ~3.3 μm in BiSbTe₁.₅Se₁.₅ and with irregularly shaped grains with the average size of ~18.9 μm in PbSnTeS

Effect of the synthesis method on the phase composition and magnetism of layered double hydroxides

A number of tetrametallic layered double hydroxides containing magnesium and cobalt on the site of doubly charged cations in the structure of brucite-like layers and aluminum and iron on the site of triply charged cations have been synthesized using three distinct methods: coprecipitation, microwave synthesis, and hydrothermal crystallizatio