DISPERSE FERROMAGNETIC: A CONTROL OF MAGNETIC PROPERTIES OF SAMPLE AND ITS MATERIAL (QUASICONTINUOUS). CRITERION OF SAMPLE’ RELATIVE LENGTH

For a specially obtained family of dependences of the magnetic induction B in a dispersed (granular) sample on its relative length λ in the range λ = 1÷13 (at different values of the magnetizing field strength H), criterion values λ = [λ] were found using a previously tested method. At these values, the dependence B on λ reaches the self-similarity region (“plateau”), and therefore, at λ ≥ [λ], when the demagnetizing factor of the sample is minimized, the magnetic properties of the sample correspond to those of its material. In the studied range of H = 14÷131 kA/m criterion value [λ] = 7.8÷4.9 and the obtained decreasing H-dependence on [λ] obeys the inverse power function with a power equals to 0.2. According to data B (at λ ≥ [λ]), values of magnetic permeability μ of quasisolid material of samples, as well as H-dependence on μ partially located (from H = 14 kA/m to H = 30÷35 kA/m) in the vicinity of extremum μ = 6 and then decreasing to μ = 3.5, were obtained. Due to this dependence, including its established functional type (exponential at H ≥ 35 kA/m), the μ-dependence on [λ] was found with variants of its functional legalization: both on the basis of the mentioned power H-function of [λ] and by exponential function.