Magnetoacoustic effects of composite films CoFeB/SiO$_2$ with different magnetic structure excited by nanosecond laser pulses

Experiments on excitation of elastic pulses by nanosecond laser pulses were carried out and their propagation in composite films (CoFeB/SiO$_2$) with different magnetic structures was studied. The highest amplitude of excited elastic pulses was observed in films with a strip magnetic structure. Maxima of the amplitude and power of the components of the spectrum of elastic pulses were found at frequencies of 61 and 72 MHz for films with a strip magnetic structure, which are associated with oscillations of the magnetic stripes of the structure excited by a laser nanosecond pulse. It was shown that a two-layer lavsan-composite film can play the role of an acoustic resonator for excited elastic pulses at the frequencies studied.