Study of energy dissipation in a suspension of particles with magnetic hysteresis in alternating supercritical-frequency field

Results of the experimental study of energy dissipation in a dielectric suspension of magnetohard γ-Fe₂O₃ particles exposed to alternating magnetic field with a frequency exceeding the limiting frequency of mechanical rotations of ferroparticles in a carrier liquid are reported. The rate of energy absorption is investigated as depending on the field amplitude and particle concentration. A drastic increase in the absorption is observed with a rise in the amplitude in the 450–800 Oe range. It is revealed that the energy dissipated in the suspension, as calculated per volume of ferroparticles, is maximal at low particle concentrations. When the concentration increases, the energy dissipation decreases by one-third becoming equal to that in a solid unordered ferrodispersion. The results obtained qualitatively agree with the theory of dissipation in suspensions of single-domain particles characterized by a magnetic hysteresis.