Oscillatory buckling reversal of a weak stripe magnetic texture.

By combining volume sensitive high resolution Magnetic Force Microscopy with surface sensitive X-ray Photoemission Electron Microscopy, we resolved the depth profile of a weak stripe magnetic texture and its evolution upon in-plane magnetization reversal. In contrast to previous reports, we show that the conventional weak stripe texture undergoes a well-defined undulation while the magnetic field is reversed to negative after in plane positive saturation. This transformation is strongly impacting the flux closure caps domains and a staggered Néel caps texture appears. Thanks to quantitative agreement with micro-magnetic simulations, we demonstrate that the existence of both the instability and the staggered Néel caps is intrinsic in negative applied field after positive in plane saturation. This reversal mode is characterized by a checker board pattern of alternating surface magnetic charges and by a longitudinal modulation of the in-plane component of magnetization similar to the oscillatory buckling reversal mode reported in elongated soft magnetic nanostructures. Zigzaging magnetic weak stripes have been observed in CoFeB thin films. The characteristics of this new magnetic texture and its origins are revealed thanks to MFM and XMCD-PEEM measurements combined to micromagnetic simulations. [ABSTRACT FROM AUTHOR]