Numerical simulation of magnetization of 2D magnon crystals based on yttrium iron garnet films

A numerical approach based on disregarding variation in the magnetization level across the thickness of 2D ferromagnetic systems is used to calculate the hysteresis loops for the tangentially magnetized 2D magnon crystals with rhombic and square lattice symmetries obtained by means of etching cylindrical holes with a diameter of 32 μm in a 5.2-μm-thick yttrium iron garnet (YIG) film. It is demonstrated that, when the effects of the crystallographic and growth anisotropies of YIG are disregarded, the results of calculations differ from experimental magnetization curves by no more than 10%. In this case, the theoretical behavior of the lateral distribution of the magnetization with an increase in the tangential magnetic field is in qualitative agreement with the experimentally observed rearrangement of the domain structure.