Compensation walls in gallium and aluminum substituted gadolinium–bismuth–iron garnet films created by laser annealing: Measurements and simulations

Magnetic garnet films of composition $({\mathrm{Gd}}_2 {\mathrm{Bi}}_1\mathrm{) (}{\mathrm{Fe}}_{\text{4.3}} {\mathrm{Ga}}_{\text{0.2}} {\mathrm{Al}}_{\text{0.5}}\mathrm{) }{\mathrm{O}}_{12}$ are grown by liquid phase epitaxy on (111) oriented substrates of gadolininium–gallium–garnet close to magnetic compensation. Local compensation walls (CW) are fabricated by laser annealing. Images of parallel and antiparallel compensation walls and of Bloch walls in annealed regions are obtained by magnetic force microscopy (MFM). The MFM signals associated with the CWs turned out to be smaller in amplitude but broader in space than the signals created by Bloch walls. To simulate the experimental results a theoretical model is developed taking into account the broadening of the CW by the preparation technique. Very good agreement between measurements and numerical simulations is obtained.