Pulse elastic effects in composite films (CoFeB+SiO$_2$) with different structures excited by laser nanosecond pulses

The work includes experiments on excitation of elastic pulses in composite films (CoFeB+SiO$_2$) with different structures by laser nanosecond pulses. It is shown that on the time dependence of the electric voltage on the piezoelectric plate, arising under the action of elastic pulses excited in composite films with different structures, a region of minimum negative voltage $U_\text{п}$ occurs. For composite films with a granular structure, at large times of about 0.4 $\mu$s, a relaxation decrease in the negative voltage is observed. For composite films with a metal strip structure, damped quasi-periodic oscillations of voltage on the piezoelectric plate are observed. The highest amplitude of the negative voltage on the piezoelectric plate was observed for a composite film with a strip metal structure, which was in conductive contact with the piezoelectric plate. The results obtained in the work can be useful for studying the structure in thin composite films on dielectric substrates, as well as for creating an amplifier of acoustic pulses and information processing devices.