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Abstract
Attention is drawn to the lack of experimental data allowing one to judge the magnetic properties of concentrated disperse magnets with different values of the ratio of the cylindrical sample’s length L to its diameter D. Data have been obtained for magnetic induction, permeability, susceptibility, and magnetization for granular samples in the form of a backfill of ferromagnetic balls at different magnitudes of L/D (1–16). It has been found that within the accepted range of intensity of the magnetizing field equals 9–47 kA/m, the permeability and susceptibility correspond to values in the region of weakly expressed extrema of their field dependences and therefore are almost stable, while the field dependences of induction and magnetization demonstrate a noticeable (only with slightly decreasing intensity) growth, what indicates the absence of magnetic saturation of granular (as opposed to solid) magnets. It has been shown that with an increase in L/D the studied magnetic parameters grow to a certain value L/D = [L/D] (at L/D ≥ [L/D] the magnetic properties of the sample correspond to its potential magnetic properties, i.e. its quasi-solid material). For such samples, this transitional (to a certain extent criterion) value of L/D is [L/D] = 10–12, i.e. significantly lower than for solid samples, in particular, made of steel. The exponential dependence of the demagnetizing factor N of “short” samples (1 ≤ L/D < [L/D]) on such an argument as the power function L/D with an exponent of power equals 0.5–0.6.
Acknowledgements
The research was carried out with the financial support of the Ministry of Science and Higher Education of the Russian Federation, Project No. 0706-2020-0024.