Ultrasonic study of the effect of time of the ferrofluid exposure to magnetic field on its structure

Abstract The properties of ferrofluids depend on the effect of the magnetic field acting on them, i.e. on the field intensity and the mode of its application. This paper reports results of an ultrasonic experimental study of a ferrofluid subjected to a magnetic field that was applied in to ways: stepped up and swept continuously. The parameter measured was the velocity of propagation of the ultrasonic wave. On the basis of the results, the effect of time of the external magnetic field application on the ferrofluid was analysed.