The magnetic dipole-dipole interaction effect on the magnetic hysteresis at zero temperature in nanoparticles randomly dispersed within a plane

•Hysteresis loops of randomly distributed nanoparticles were calculated.•The non-monotonic behavior of coercive force is induced by dipole-dipole interaction.•Coercive force is determined by the magnetic anisotropy and the dipole energy. The dipole-dipole interaction effect on the magnetic hysteresis of nanoparticles randomly dispersed within a plane is studied by micromagnetic simulation. The dependence of the coercive field with the concentration of nanoparticles varies from nonlinear and monotonic to non-monotonic dependence with a maximum at a certain concentration. It happens when the ratio of the magnetic anisotropy constant to the maximal dipole energy changes from value much larger than 1 to the value much less than unity.