Absence of stable collinear configurations in Ni(001)ultrathin films: canted domain structure as ground state

摘要

Brillouin light scattering (BLS) measurements were performed for (17-120)Angstrom thick Cu/Ni/Cu/Si(001) films. A monotonic dependence of the frequencyof the uniform mode on an in-plane magnetic field H was observed both onincreasing and on decreasing H in the range (2-14) kOe, suggesting the absenceof a metastable collinear perpendicular ground state. Further investigation bymagneto-optical vector magnetometry (MOKE-VM) in an unconventional canted-fieldgeometry provided evidence for a domain structure where the magnetization iscanted with respect to the perpendicular to the film. Spin wave calculationsconfirm the absence of stable collinear configurations.