Spark Plasma Sintering (SPS)-Assisted Synthesis and
Thermoelectric Characterization of Magnéli Phase V6O11
The Magnéli 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 Magnéli-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 = −(35 ± 2) μV K–1, which leads to a power factor of PF = 4.9 ± 0.8 × 10–5W (m K2)−1 at ∼600 K. Advances in the application of Magnéli phases are mostly hindered by synthetic and processing challenges, especially when metastable and nanostructured materials such as V6O11 are involved. This study gives insight into the compli...
Markus Joos; Giacomo Cerretti; Igor Veremchuk; Patrick Hofmann; Hajo Frerichs; Dalaver H. Anjum; Tobias Reich; Ingo Lieberwirth; Martin Panthöfer; Wolfgang G. Zeier; Wolfgang Tremel
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