Regensburg 2016 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 3: Correlated Electrons: Frustrated Magnets - Pyrochlore Systems and Iridates

TT 3.3: Vortrag

Montag, 7. März 2016, 10:00–10:15, H20

Magnetoelastic properties of the quantum-spin-ice candidate Yb₂Ti₂O₇ — •T. Stöter^1,2,3, M. Doerr^1,2, S. Granovsky^1,2, Z.S. Wang^1,2,3, S. Erfanifam³, E. Green³, S. Zherlitsyn^1,3, J. Wosnitza^1,2,3, A. Maljuk^1,4, and S. Wurmehl^1,4 — ¹SFB 1143 — ²TUD/IFP, Dresden — ³HZDR, Dresden — ⁴IFW, Dresden

Intriguing phenomena such as the occurrence of magnetic monopoles and a wide variety of ground states are associated to magnetic frustration. In a number of cases, elastic effects, e.g. lattice distortions, may result in the lifting of degeneracies or the appearance of new magnetic states. The rare-earth titanate Yb₂Ti₂O₇, where the magnetic Yb³⁺ ions form a pyrochlore spin network, is a prime example of a geometrically frustrated material, with numerous field-induced phases and strong ferromagnetic correlations below 170 mK. In order to characterize the magneto-elastic coupling in this material, we have investigated the thermal expansion, magnetostriction, and sound propagation in different dilution refrigerators between 60 mK and 1.5 K and large applied magnetic fields. At around 170 mK we find distinct anomalies in the expansion coefficient, acoustic properties, as well as the specific heat. Lattice anomalies in field hint to additional low temperature phases.