Fig. 1: Magnetic characterization and DW structure of the film.
From: Néel domain walls with bistable chirality in a perpendicularly magnetized ferrimagnetic insulator
a SMR data and modeled fit to extract the anisotropy energies. Transverse Hall resistances (\({R}_{{{\rm{H}}}}\)) are measured as a function of applied field (\(H\)) along IP easy (IPE), IP hard (IPH), and OOP directions, corresponding to [\(\bar{1}\)10] (defined as \(\hat{{{\bf{x}}}}\)), [001] (defined as \(\hat{{{\bf{y}}}}\)), and [110] (defined as \(\hat{{{\bf{z}}}}\)) directions, respectively. The square hysteresis loop (green circles) indicates that the lowest anisotropy energy axis is OOP, [110], and the slope originates from the ordinary Hall effect. A zoomed-in plot of the OOP hysteresis loop with a field range of \(\pm\)2000 Oe is shown in the inset. The OOP anisotropy energy density, \({K}_{u,{{\rm{OOP}}}}^{{{\rm{eff}}}}\) is extracted from the saturation field, \({H}_{k,{{\rm{OOP}}}}^{{{\rm{eff}}}}\) of the [\(\bar{1}\)10] data (yellow circles). The IP anisotropy energy density, \({K}_{u,{{\rm{IP}}}}\) is extracted from \({H}_{k,{{\rm{IP}}}}\), the difference between the saturation fields of the [001] (blue circles) and [\(\bar{1}\)10] data. The red solid curves are modeled fits to the experimental data, which give \({H}_{k,{{\rm{OOP}}}}^{{{\rm{eff}}}}\) = 2810 Oe and \({H}_{k,{{\rm{IP}}}}\) = 5100 Oe. A schematic of the Hall cross device, along with the \(\hat{{{\bf{x}}}}\), \(\hat{{{\bf{y}}}}\), \(\hat{{{\bf{z}}}}\) coordinate system throughout this paper, is shown in the inset. b Surface plot of the measured anisotropy landscape. The energy density along the lowest energy axis, [110], is taken as the zero reference. (i) Polar plot of the projected energy density landscape on the (001) vertical plane. (ii) Polar plot of the projected energy density landscape on the (110) film plane. c Schematics of DW track configuration for Néel wall stabilization and of fully Néel CCW and CW DW spin structures stabilized in the film by the strong IP anisotropy corresponding to the wall center spins oriented to the left (red arrow) and to the right (blue arrow) for up-down and down-up walls.
