Figure 2
From: Manipulating Topological States by Imprinting Non-Collinear Spin Textures
Visualising magnetic spin textures by means of MTXM and XPEEM.
(a) Schematics of the investigated layer stack and SEM cross-section of the sample. Magnetic hysteresis loops of Co/Pd spins for different Pd spacer thickness d reveals peculiar properties of the approach. (b) Contrast origin for curved non-collinear textures (XMCD contrast calculated, not normalised). The wavy pattern indicates regions of very weak/absent XMCD contrast. (c), (d) MTXM (brown and gray shaded) and XPEEM (red-blue colorspace) images of the remanent state of closely packed CoPd/Pd(d)/Py caps with various Pd spacer thickness reveal non-collinear spin textures in Co/Pd. (c) For 1 nm Pd spacer thickness, Py and Co/Pd spins form a vortex with the same circulation (left and right circulation labelled by red and green circles). (d) Samples with 4 ~ 5 nm-thick Pd spacer show stronger out-of-plane contrast and the numerically predicted states: red – donut state type I; cyan – donut state type II; purple – spiral state; gray – ambiguous. (See text for information about magnetic fields applied before.) The scale bar is 500 nm. (e) Line profiles. The core size of the donut state ranges from 60 to 110 nm. The XPEEM data within each cap exhibits a small asymmetry originating from a small in-plane magnetisation component of the Co/Pd spins. (In-plane contrast of images at Co Ledge is enhanced for better visualisation.)
