Regensburg 2016 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 28: Correlated Electrons: Quantum-Critical Phenomena - Experiment

TT 28.7: Vortrag

Dienstag, 8. März 2016, 11:45–12:00, H21

ACRT technique for the single crystal growth of the heavy fermion compound YbRh₂Si₂ — •Sebastian Witt, Kristin Kliemt, Constantin Butzke, and Cornelius Krellner — Goethe University Frankfurt, 60438 Frankfurt am Main, Germany

In the heavy fermion compound YbRh₂Si₂ the antiferromagnetic ordering below 70 mK close to a quantum criticial point is well-studied. Beneath the magnetic ordering a new phase transition was found recently at 2 mK. [1] It is necessary to prepare large and high-quality single crystals for studying the nature of this new phase transition. Besides the optimization of the single crystal growth it is important to investigate single crystals with different isotopes at this phase transition.

Here, we report the crystal growth of YbRh₂Si₂ with the accelerated crucible rotation technique (ACRT). ACRT shows for other compounds, e.g. YAG (yttrium aluminum garnet, Y₃Al₅O₁₂), that this technique can reduce flux impurities and enhance the yield of larger crystals. We also report the attempt to receive metallic isotopes of ytterbium with metallothermic reduction. Crystals with different isotopes of silicon and ytterbium can be used for NMR measurements to investigate the underlying phenomena of quantum criticality in more detail.

[1] Schuberth et al., J. Phys.: Conf. Ser. 150 (2009) 042178.