EXCITATIONS OF STRIPE DOMAIN LATTICES IN PERPENDICULARLY MAGNETIZED GARNET-FILMS

Magnetic garnet films of composition Y3-xBixFe5-yAlyO12 are grown by l iquid phase epitaxy on [111] and [110] oriented substrates of gadolini um gallium garnet. They have high uniaxial anisotropy and support latt ices of parallel stripe domains. The two branches DR(+) and DR(-) of t he domain resonance are excited by rf magnetic fields polarized in the film plane. Resonance frequencies of more than 7 GHz are observed; th ey are measured as function of a static induction B-perpendicular to a pplied perpendicular to the film plane. With increasing B-perpendicula r to the resonance mode DR(+) is confined to the small domain with equ ilibrium magnetization antiparallel to B-perpendicular to, while DR(-) is confined in the larger stripe having equilibrium magnetization par allel to B-perpendicular to. At the collapse induction the DR(-) mode merges into the ferrimagnetic resonance. The resonance modes DR(+/-) a re calculated using a new method to determine the demagnetizing energy . Excellent agreement between theory and experiment is obtained.