Thermoelectric clathrates hold significant promise for high temperature applications with zT values exceeding 1.3. The inorganic have been shown to be both chemically and thermally stable at temperatures, performance can obtained from single crystals processed powders. also show excellent compatibility factors in segmented module applications. For a materials chemist it is furthermore of great importance that the exhibit very rich chemistry ability substitution many different elements. This...

Abstract Recently, a large number of nanostructured metal‐containing materials have been developed for the electrochemical CO 2 reduction reaction (eCO RR). However, it remains challenge to achieve high activity and selectivity with respect metal load due limited concentration surface atoms. Here, is reported that bismuth‐based metal–organic framework Bi(1,3,5‐tris(4‐carboxyphenyl)benzene), herein denoted Bi(btb), works as precatalyst undergoes structural rearrangement at reducing potentials...

The synthesis of aluminum-substituted strontium hexaferrite nanoparticles (SrFe12-xAlxO19 with x = 0–3), via three different preparation methods, is investigated. methods are hydrothermal autoclave (AC) synthesis, a citrate sol–gel (SG) and solid-salt matrix (SSM) synthesis. Evaluation macroscopic magnetic properties lattice parameters obtained by Rietveld analysis powder X-ray diffraction (PXRD) data indicate that successful substitution Al into the crystal structure only achieved for SG...

Multi-temperature X-ray diffraction studies show that twisting, rotation, and libration cause negative thermal expansion (NTE) of the nanoporous metal−organic framework MOF-5, Zn4O(1,4-benzenedicarboxylate)3. The near-linear lattice contraction is quantified in temperature range 80−500 K using synchrotron powder diffraction. Vibrational motions causing abnormal behavior are evidenced by shortening certain interatomic distances with increasing according to single-crystal on a guest-free...

The formation and growth mechanisms in the hydrothermal synthesis of SnO(2) nanoparticles from aqueous solutions SnCl(4)·5H(2)O have been elucidated by means situ X-ray total scattering (PDF) measurements. analysis data reveals that when tin(IV) chloride precursor is dissolved, ions water coordinate octahedrally to tin(IV), forming aquachlorotin(IV) complexes form [SnCl(x)(H(2)O)(6-x)]((4-x)+) as well hexaaquatin(IV) [Sn(H(2)O)(6-y)(OH)(y)]((4-y)+). Upon heating, ellipsoidal are formed...

Transport properties of ${\mathrm{Ba}}_{8}{\mathrm{Ga}}_{16}{\mathrm{Ge}}_{30}$ single-crystalline samples prepared with an excess Ga are presented. The does not only produces p-type transport but also a thermal conductivity (\ensuremath{\kappa}) that, unlike in any other reported the literature, is similar to that iso-structural ${\mathrm{Eu}}_{8}{\mathrm{Ga}}_{16}{\mathrm{Ge}}_{30}$ and ${\mathrm{Sr}}_{8}{\mathrm{Ga}}_{16}{\mathrm{Ge}}_{30}.$ These observations disagree commonly made...

Comprehensive single-crystal structural investigations of n- and p-type Ba8Ga16Ge30 have been carried out using multitemperature neutron conventional X-ray diffraction as well resonant synchrotron diffraction. The data show that the guest atom positions dynamics are very similar in two structures, although barium atoms slightly more displaced from cage centers structure than n-type (Deltad = 0.025 A). For both structures Fourier difference maps calculated high-resolution (sin theta/lambda >...

The high thermoelectric figure of merit $(zT)$ ${\mathrm{Ba}}_{8}{\mathrm{Ga}}_{16}{\mathrm{Ge}}_{30}$ makes it one the best $n$-type materials for power generation. Here, we describe synthesis and characterization a Czochralski pulled single crystal polycrystalline disks. Measurements electrical conductivity, Hall effect, specific heat, coefficient thermal expansion, Seebeck were performed up to $1173\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ compared with literature results. Dilatometry...

The crystal and magnetic structures of MFe₂O₄ (M = Mn, Co, Ni, Zn) nanoparticles are determined by combined X-ray neutron diffraction data modelling related to the macroscopic properties.

The growing interest in inorganic nanoparticles for a wide range of applications is spurring need synthesis methods that allow highly specific tailoring material properties. Synthesis supercritical fluids holds great promise solving this problem, but so far the fundamental chemical processes taking place under these conditions are to large extent unknown. Here design, construction and application versatile experimental setup reported; enables situ synchrotron small-angle X-ray...

Abstract The extraordinary thermoelectric properties of lead chalcogenides have attracted huge interest in part due to their unexpected low thermal conductivity. Here, it is shown that anharmonicity and large cation disorder are present both PbTe PbS, based on elaborate charge density visualization using synchrotron powder X‐ray diffraction (SPXRD) data analyzed with the maximum entropy method (MEM). In systems, increases increasing temperature, whereas Te/S anions appear be centered...

The nucleation, crystallization, and growth mechanisms of MnFe2O4, CoFe2O4, NiFe2O4, ZnFe2O4 nanocrystallites prepared from coprecipitated transition metal (TM) hydroxide precursors treated at sub-, near-, supercritical hydrothermal conditions have been studied by in situ X-ray total scattering (TS) with pair distribution function (PDF) analysis, synchrotron powder diffraction (PXRD) Rietveld analysis. TS experiments were carried out on 0.6 M TM aqueous chloride solutions using 24.5% NH4OH...

Abstract The experimental electron density of the high‐performance thermoelectric material Zn 4 Sb 3 has been determined by maximum entropy (MEM) analysis short‐wavelength synchrotron powder diffraction data. These data are found to be more accurate than conventional single‐crystal due reduction common systematic errors, such as absorption, extinction and anomalous scattering. Analysis MEM directly reveals interstitial atoms a partially occupied main site. Two types observed: free spherical...

A simple biomolecule-assisted hydrothermal approach has been developed for the fabrication of Bi2Te3 thermoelectric nanomaterials. The product a nanostring-cluster hierarchical structure which is composed ordered and aligned platelet-like crystals. platelets are ∼100 nm in diameter only ∼10 thick even though high reaction temperature 220 °C long time 24 h were applied to prepare sample. growth appears be self-assembly process. Initially, Te nanorods formed using alginic acid as both...

The crystal structure and defect chemistry of hydrothermally synthesized LiFe1-xMnxPO4 (x = 0, 0.25, 0.50) particles have been characterized by simultaneous neutron X-ray Rietveld refinement as well pair distribution function (PDF) analysis, crystallinity determination, Mössbauer spectroscopy, ion coupled plasma (ICP) studies, scanning electron microscopy (SEM). very detailed structural refinements show that fast hydrothermal synthesis causes partial Fe-occupancy vacancies on the Li (M1)...

Supercritical growth: The formation and evolution of ceria nanoparticles during hydrothermal synthesis was investigated by in situ total scattering powder diffraction. nucleation pristine crystalline originated from previously unknown cerium dimer complexes. nanoparticle growth highly accelerated under supercritical conditions.

The formation and growth of maghemite (γ-Fe2O3) nanoparticles from ammonium iron(III) citrate solutions (C6O7H6·xFe3+·yNH4) in hydrothermal synthesis conditions have been studied by situ total scattering. local structure the precursor solution is similar to that crystalline coordination polymer [Fe(H2cit(H2O)]n, where corner-sharing [FeO6] octahedra are linked citrate. As treatment initiated, clusters edge-sharing units form (with extent structural order <5 Å). Tetrahedrally coordinated iron...

Nanocrystallites of the permanent magnetic material SrFe12O19 were synthesised using a conventional sol-gel (CSG) and modified (MSG) synthesis route. In MSG synthesis, crystallite growth takes place in solid NaCl matrix, resulting freestanding nanocrystallites, as opposed to CSG where produced nanocrystals are strongly intergrown. The nanocrystallites from both methods exhibit similar intrinsic properties, but significantly different morphology degree aggregation. compacted into dense...

Three Ba8Al16Ge30 clathrate type I samples have been prepared using three different synthesis methods; flux growth, Czochralski and stoichiometric mixing. The were characterized by X-ray powder diffraction, multi-temperature single-crystal high-resolution low-temperature (20 K) neutron measurement of transport properties. show a remarkable variation in the aluminum/germanium occupancies on host-structure sites minor total aluminum content. observed occupancy forms basis for formulation set...

We have investigated the formation of ZnO nanoparticles using a fast continuous flow hydrothermal synthesis method. The conditions been varied with respect to temperature, pH, and concentration Zn(NO3)2·4H2O + NaOH aqueous precursor. different affect size, morphology, crystallinity produced nanoparticles. were by Rietveld refinement powder X-ray diffraction data, transmission electron microscopy, scanning microscopy. particle size morphology are highly temperature dependent: Anisotropic...

Zinc antimonide thin films with high thermoelectric performance are produced by a simple sputtering method. The phase-pure Zn4Sb3 and ZnSb fulfill the key requirements for commercial TE power generation: cheap elements, fabrication method, thermal stability. In addition, two completely new meta-stable crystalline phases of zinc have been discovered. Detailed facts importance to specialist readers published as "Supporting Information". Such documents peer-reviewed, but not copy-edited or...

Solid state synthesis of Li4Ti5O12 anode material for Li ion batteries typically results in products containing rutile TiO2 and Li2TiO3 impurities, subsequent high calcination temperatures lead to particle growth that reduces capacity rate ability. Here, the formation particles by a solid-state reaction using anatase with various crystallite sizes Li2CO3 is investigated situ temperature powder X-ray diffraction (HT-PXRD) thermal gravimetry-differential analysis (TG-DTA). The combined data...