From ferro- to antiferromagnetism via exchange-striction ofH. Yamaguchi, A. K. Das, A. Ney, T. Hesjedal, C. Pampuch, D. M. Schaadt and R. Koch
Paul-Drude-Institut für Festkörperelektronik - Hausvogteiplatz 5-7 D-10117 Berlin, Germany
received 22 July 2005; accepted in final form 8 September 2005
published online 30 September 2005
We investigated the stress evolution in single-crystal films on upon applying high external magnetic fields in the phase transition regime (10-40 C) and beyond. Our stress measurements reveal large field-induced lattice distortions at temperatures, where - is present, even well above the phase transition ( C). A quantitative comparison with the field-induced increase of magnetization reveals that the changes in the lattice dimensions can be fully explained by the (reversible) back-transformation of - to - . Our direction-dependent experiments identify the structural distortions at the phase transition as a volume magnetostriction effect and -due to the persisting magnetocrystalline anisotropy above C- strongly support an antiferromagnetic state for -
75.70.Ak - Magnetic properties of monolayers and thin films.
68.60.Bs - Mechanical and acoustical properties.
75.80.+q - Magnetomechanical and magnetoelectric effects, magnetostriction.
© EDP Sciences 2005