Dresden 2009 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 28: Focused Session: Spin Transport and Coherence in Emerging Materials
MA 28.7: Vortrag
Mittwoch, 25. März 2009, 17:15–17:30, HSZ 101
Magnet heat transport of impurity doped spin chains — •N. Hlubek, C. Hess, U. Schaufuss, V. Kataev, C. Sekar, G. Krabbes, and B. Büchner — Leibniz-Institute for Solid State and Materials Research, IFW Dresden, 01171 Dresden, Germany
We investigate the magnetic thermal conductivity κmag of the spin chain material CaCu2O3 doped with non-magnetic Zn impurities. κmag of the pure compound is linear up to room temperature which is indicative of a T-independent scattering rate of the magnetic excitations [1]. Both, magnitude and T-dependence of κmag exhibit a very unusual doping dependence. At moderate Zn-doping the linear temperature dependence of κmag is preserved and the absolute value of κmag increases. A slight suppression of κmag occurs only at high Zn doping, where, surprisingly, the T-dependence of κmag changes from linearity to one with a higher power of T. In order to clarify this surprising behavior, we have performed a detailed study of the g-tensor of the impurities in the material by means of ESR experiments which reveals change of impurity type with increasing Zn-content.
[1] C. Hess et al., Phys. Rev. Lett. 98, 027201 (2007).