0000000000422019
AUTHOR
Igor Veremchuk
showing 5 related works from this author
SPS-assisted preparation of the Magnéli phase WO2.90 for thermoelectric applications
2013
We describe the preparation and simultaneous consolidation of WO2.90 by spark plasma sintering (SPS). SPS allows for the direct manufacturing of large amounts of consolidated material. Synchrotron powder X-ray diffraction indicates that the material is single phase. Microstructure analysis indicates that the pellet is fully dense, allowing high-temperature thermoelectric properties to be reliably measured. The as-prepared samples of WO2.90 reach a ZT of 0.1 at 1100 K.
Spark Plasma Sintering (SPS)-Assisted Synthesis and Thermoelectric Characterization of Magnéli Phase V6O11
2018
The Magneli phase V6O11 was synthesized in gram amounts from a powder mixture of V6O11/V7O13 and vanadium metal, using the spark plasma sintering (SPS) technique. Its structure was determined with synchrotron X-ray powder diffraction data from a phase-pure sample synthesized by conventional solid-state synthesis. A special feature of Magneli-type oxides is a combination of crystallographic shear and intrinsic disorder that leads to relatively low lattice thermal conductivities. SPS prepared V6O11 has a relatively low thermal conductivity of κ = 2.72 ± 0.06 W (m K)-1 while being a n-type conductor with an electrical conductivity of σ = 0.039 ± 0.005 (μΩ m)-1, a Seebeck coefficient of α = -(3…
Thermoelectric properties of spark-plasma sintered nanoparticular FeSb2prepared via a solution chemistry approach
2013
Nanoparticular FeSb2 was prepared in solution from cyclopentadienyl iron(ii) dicarbonyl dimer [Fe(Cp(CO)2)]2 and antimony nanoparticles. Spark plasma sintering was used as consolidation method to maintain the particle size. The thermoelectric performance of FeSb2 is limited by its high thermal conductivity. In this work, the thermal conductivity was suppressed by nearly 80% compared to the bulk value by introducing grain boundary scattering of phonons on the nanoscale. The thermoelectric properties of the consolidated FeSb2 emphasize the possibility of altering thermal transport of promising thermoelectric compounds by phonon scattering by engineering the interfaces at the nanoscale.
Using crystallographic shear to reduce lattice thermal conductivity: high temperature thermoelectric characterization of the spark plasma sintered Ma…
2013
Engineering of nanoscale structures is a requisite for controlling the electrical and thermal transport in solids, in particular for thermoelectric applications that require a conflicting combination of low thermal conductivity and low electrical resistivity. We report the thermoelectric properties of spark plasma sintered Magnéli phases WO2.90 and WO2.722. The crystallographic shear planes, which are a typical feature of the crystal structures of Magnéli-type metal oxides, lead to a remarkably low thermal conductivity for WO2.90. The figures of merit (ZT = 0.13 at 1100 K for WO2.90 and 0.07 at 1100 K for WO2.722) are relatively high for tungsten-oxygen compounds and metal oxides in general…
Enhanced thermoelectric properties of the n-type Magnéli phase WO2.90: reduced thermal conductivity through microstructure engineering
2014
The thermoelectric properties of the Magneli phase WO2.90 were investigated, with special attention to how the thermoelectric performance can be altered by changing its microstructure. Spark plasma sintering (SPS) allowed the direct preparation of large amounts of consolidated material. Adding Ta2O5 to the reaction mixture lead to the formation of solid solutions W1−xTaxO2.90via a concurrent reaction between WO3 and Ta2O5 during the SPS treatment. In addition, micron-sized inclusions containing tungsten surrounded by WOx embedded in a WO2.90 matrix were formed, which act as additional scattering centers. As a result, the thermal conductivity of the Ta-containing samples was reduced by ≈30% …