Regensburg 2019 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 23: Frustrated Magnets - General 1 (joint session TT/MA)

TT 23.3: Vortrag

Dienstag, 2. April 2019, 10:00–10:15, Theater

Phase diagram of the pseudo-Kagome francisite Cu₃Bi(SeO₃)₂O₂Cl studied by high-resolution dilatometry — •Sven Spachmann¹, Liran Wang¹, Alexander Vasiliev², and Rüdiger Klingeler¹ — ¹Kirchhoff Institute for Physics, Heidelberg, Germany — ²Lomonosov Moscow State University, Moscow, Russia

Single crystals of the layered Kagome-like francisite Cu₃Bi(SeO₃)₂O₂Cl have been studied by high-resolution thermal expansion and magnetostriction as well as by bulk magnetization measurements. At B=0 T, in addition to a well-known structural phase transition at T_s=120 K, long range antiferromagnetic order of the ferromagnetically coupled layers develops around T_N = 26.4 K. The ordering is associated with pronounced anomalies in the uniaxial thermal expansion coefficients. Magnetic fields yield a suppression of T_N. In plane, a sign change of the uniaxial pressure dependencies (at B>2 T for B||a) signals a change in the nature of the phase transition. At T=2 K, metamagnetic transitions are observed for B parallel to the (in-plane) a-, b-, and (out-of-plane) c-axes at B_C = 5.4 T, 1.6 T, and 0.9 T, respectively. The transitions are associated with sharp magnetization jumps. The magnetic phase diagram for all three crystal axes is constructed and discussed.