Regensburg 2016 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 3: Correlated Electrons: Frustrated Magnets - Pyrochlore Systems and Iridates
TT 3.9: Vortrag
Montag, 7. März 2016, 11:45–12:00, H20
Specific heat study of the iridium double perovskite Sr2YIrO6 — •Laura T. Corredor, Kaustuv Manna, Gizem Aslan Cansever, Sebastian Gass, Andreas Zimmermann, Tushar Dey, Christian Blum, Andrey Maljuk, Sabine Wurmehl, Anja Wolter, and Bernd Büchner — Leibniz Institute for Solid State and Materials Research IFW, Institute for Solid State Research, 01069 Dresden, Germany
Recently, Mott insulators with a d4 electronic configuration were predicted to show superexchange-driven quantum phase transitions. Double perovskites R2MM′O6 with
M′ 3+ ion, yielding a formal oxidation state of Ir5+ with 5d4 electronic configuration, may be candidates to verify or discard such
transitions and its impact on the magnetic structure. According to the strong spin-orbit coupling Jeff model, a non-magnetic ground state is expected. Such material is realized in
Sr2YIrO6. Nevertheless, it is claimed [1] that a strong non-cubic crystal field together with a “intermediate-strength” spin-orbit coupling, would
lead to a different ground state configuration and to antiferromagnetic behavior with TN = 1.3 K. Also, anomalies in the specific heat were associated to this novel
magnetism. In this work, we present magnetic and thermodynamic characterization of Sr2YIrO6 single crystals. No long magnetic order was found. The magnetic contribution to the
specific heat was calculated, finding a Schottky anomaly due to magnetic impurities. Further analysis suggests non-negligible spin correlations, which nonetheless, are not associated with long
range magnetic ordering.
G.Cao et al., PRL 112, 056402 (2014).