By tuning the incidence angle of hard, circularly polarized x-rays with respect to the sample surface, we are able to independently probe surface and bulk magnetic states in a Fe(35 Å)[Gd(50 Å)/Fe(35 Å)]15 ferrimagnetic multilayer by magnetic circular dichroism (MCD). We show that a twisted magnetic state nucleates at the surface of the multilayer at T≈0.7 Tcomp, where Tcomp is the ferrimagnetic compensation temperature. At nucleation, the twist penetrates ≈170 Å or two bilayers. Despite its theoretical prediction by LePage and Camley more than 15 years ago [J. G. LePage and R. E. Camley, Phys. Rev. Lett. 65, 1152 (1990); R. E. Camley, Phys. Rev. B 35, 3608 (1987)], this surface-twisted state has eluded direct experimental detection up to now. Its clear observation here demonstrates the power of grazing incidence, hard x-ray, MCD measurements for studies of magnetic phase transitions in layered structures.
No takes yet. Share an insight, caveat, or question.
Haskel et al. (2003) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: