Dresden 2006 – wissenschaftliches Programm
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MA: Magnetismus
MA 26: Electron Theory
MA 26.4: Vortrag
Donnerstag, 30. März 2006, 11:00–11:15, HSZ 401
Spontaneous magnetostriction in elemental ferromagnets investigated with a DLM approach — •Ulrike Nitzsche, Manuel Richter, Klaus Koepernik, and Helmut Eschrig — IFW Dresden, P.O. Box 270116, D-01171 Dresden, Germany
The large change of lattice parameters caused by magnetic order of elemental
hcp Gd was been a subject of intensive studies in the past. In several
ab-initio calculations the value of the spontaneous volume magnetostriction of
Gd was overestimated by a factor of 2 to 4. An important point is the
modelling of the paramagnetic state of Gd above TC characterized by the non-vanishing
fluctuating f-moments. Besides the usually used method to model this state by a supercell with ordered antiferromagnetic spin configurations one can simulate the magnetic disorder in the paramagnetic state by disordered local moments (DLM) within the coherent potential approximation (CPA).
Up to now no comparison of both models has been published using the same numerical
method. Aim of this talk is to investigate the influence of the different models for the paramagnetic state on the value of the spontaneous magnetostriction for the elemental ferromagnets Gd, Fe and Ni. Additional contributions to the spontaneous magnetostriction are discussed.