Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

MA: Magnetismus

MA 5: Spinstrukturen und magnetische Phasenüberg
änge

MA 5.7: Vortrag

Freitag, 4. März 2005, 12:00–12:15, TU EMH225

Magnetism of weakly doped spin chains in La5Ca9Cu24O41 — •R. Leidl1, R. Klingeler2, B. Büchner2, W. Selke1, and M. Holtschneider11Institut für Theoretische Physik, RWTH Aachen, 52056 Aachen, Germany — 2IFW Dresden, PF 270116, 01171 Dresden, Germany

Recent experiments revealed rather surprising magnetic properties of weakly hole doped spin chains in the “telephone number” compound La5Ca9Cu24O41. In particular, at low magnetic fields a small anomaly, indicating a phase transition, in the susceptibility curves (and other quantities) is observed, followed by a rather broad maximum at higher fields where one would usually expect a spin-flop transition. In an effort to (partially) understand these observations we study a classical anisotropic Heisenberg antiferromagnet with spinless holes, using mainly Monte Carlo simulations. We show that a broad maximum in the susceptibility can be caused by a disorder effect, originating in the influence of randomly distributed, immobile holes on the spin-flop transition.

100% | Bildschirmansicht | English Version | Kontakt/Impressum/Datenschutz
DPG-Physik > DPG-Verhandlungen > 2005 > Berlin