Fig. 4: Shape anisotropy of curved membranes (length = 480 μm, thickness = 100 nm) and their planar counterparts.
From: Azimuthal anisotropy induced by partial flux-closure in self-assembled tubular permalloy membranes
The illustrations show (a-i) a planar membrane and (b-i) a curved membrane, along with the coordinate system used for calculating demagnetizing factors. The anisotropy constants Ku are plotted against the closing angle for (a-ii) planar and (b-ii) curved membranes for varying radii of curvature (25 μm to 75 μm). For planar films, the closing angle is, \(\varphi =\frac{18{0}^{\circ }}{\pi }\cdot \frac{W}{R}\). Yellow arrows indicate the direction of increasing radii. a-iii, b-iii display magnified views (the shaded regions) of figures (a-ii and b-ii), focusing on the data near a 360° closing angle (equivalent to one full winding).
