title: Composition-tuning in a solid-state electrotransport furnace with active thermal expansion compensation.
abstract: A new solid-state electrotransport (SSE) apparatus for refining ultra-pure single crystals of metallic compounds under ultra-high vacuum is described. The setup employs a novel thermal expansion compensation mechanism to minimize mechanical stress on the sample during refinement with cold clamps for contamination-less purification at elevated temperatures. The apparatus is designed to tune the composition of initially slightly off-stoichiometric samples. The expansion compensation and stress-free operation were tested by recording the thermal expansion of elemental cerium in a treatment up to 655 °C. SSE refinement was then performed on a high-quality single crystal of U6Fe resulting in a 50% increase of its residual resistivity ratio to the highest value obtained for a single crystal to date.
authors.affiliation: SUPA, Centre for Science at Extreme Conditions and School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom.
authors.forename: J L
authors.initials: JL
authors.lastname: Schmehr
authors.affiliation: SUPA, Centre for Science at Extreme Conditions and School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom.
authors.forename: W
authors.initials: W
authors.lastname: Whitley
authors.affiliation: SUPA, Centre for Science at Extreme Conditions and School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom.
authors.forename: A D
authors.initials: AD
authors.lastname: Huxley