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TT: Fachverband Tiefe Temperaturen

TT 22: CE: Low-dimensional Systems - Materials 2

TT 22.2: Vortrag

Dienstag, 15. März 2011, 10:45–11:00, HSZ 304

Magnetism in the Diamond Spin Chain Azurite — •Mathias Kraken¹, Josefin Engelke¹, Stefan Süllow¹, Jochen Litterst¹, Anja Wolter², Bernd Wolf³, Michael Lang³, Chris Baines⁴, and Hubertus Luetkens⁴ — ¹IPKM, TU Braunschweig, D-38106 Braunschweig, Germany — ²Institute for Solid State Research, IFW, D-01069 Dresden, Germany — ³Physikalisches Institut, J.W. Goethe Universität, D-60438 Frankfurt (Main), Germany — ⁴SµS, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland

Azurite is a mineral, which has been proposed as a model substance for a 1D spin-1/2-Heisenberg-diamond-chain. Specific heat [1] indicated a magnetic phase transition at 1.8K, where the coupling between the 1D Cu-chains sets in. At 0.5K indications of another phase transition, with yet unknown nature, were observed [3]. Due to the small magnetic moments and the complex structure of azurite, the magnetic ground state is yet not well understood.
We performed µSR measurements at PSI on a single crystal and a powdered sample, in extension of already published µSR-data [4]. Our measurements revealed a critical behaviour of the transversal damping approaching T_c as well as clear evidence of static magnetic order below T_c. The phase transition at 0.5K is observable as well, and can be related to an alteration in the local environment of the Cu²⁺ monomers.
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