Berlin 2018 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 47: Frustrated Magnets - Iridates and Fe-based Materials

TT 47.7: Vortrag

Mittwoch, 14. März 2018, 11:00–11:15, H 0104

Magnetic ordering in the mixed valent iridate Ba₃LuIr₂O₉ — •Tusharkanti Dey¹, Mayukh Majumder¹, Jean-Christophe Orain², Anatoliy Senyshyn³, Philipp Gegenwart¹, and Alexander Tsirlin¹ — ¹EP-VI, EKM, University of Augsburg, Germany — ²Paul Scherrer Institut, Villigen PSI, Switzerland — ³FRM II, TU Munich, Germany

Mixed valent iridates with the general formula Ba₃MIr₂O₉ (M is a trivalent ion) contain face-sharing Ir₂O₉ bi-octahedra with Ir-Ir dimers along the crystallographic c-axis. In these materials, Ir has a single crystallographic site with an average charge state of +4.5. The two Ir sites within the dimer share 9 electrons among them resulting in S=1/2 moments per dimer [1]. These dimers form a triangular lattice in the crystallographic ab-plane and a buckled honeycomb lattice between the neighboring planes. We have recently synthesized polycrystalline samples of Ba₃M³⁺Ir₂^4.5+O₉ (M=In,Lu) and studied their structural and magnetic properties. In this presentation, we will discuss the results of our neutron diffraction, magnetic susceptibility, heat capacity and µSR measurements suggesting magnetically ordered ground state for Ba₃LuIr₂O₉ below 5.5 K and compare with the sister compound Ba₃InIr₂O₉ showing persistent spin dynamics and the absence of long range ordering down to 20 mK [1].
T. Dey et. al., Phys. Rev. B 96, 174411 (2017)