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Medium remanence and coercivity, two ways

The same calculation run twice, side by side. Change anything on either side and the difference is shown output by output. This page is a link: both sets of numbers are in the address bar.

Side A open alone

The magnetic solid. Its coercivity is what decides everything on this page.

%

The solid's share of the volume. The medium keeps this fraction of what each particle keeps.

µm

Below the material's single-domain limit the particle keeps half its saturation; above it, only what its coercivity can hold against its own demagnetising field.

Side B open alone

The magnetic solid. Its coercivity is what decides everything on this page.

%

The solid's share of the volume. The medium keeps this fraction of what each particle keeps.

µm

Below the material's single-domain limit the particle keeps half its saturation; above it, only what its coercivity can hold against its own demagnetising field.

Swap sides

What changed

The two sides are the same. Change something on either.

Output A B B against A
Mr Medium remanence 12 A/m 12 A/m same
Hc Coercivity 80 A/m 80 A/m same
q Remanence ratio 0.000141 0.000141 same

Side A, with its numbers

12 A/m=5 %⁢240 A/m
LaTeX 
12\,\mathrm{A/m} = 5\,\mathrm{%} \cdot 240\,\mathrm{A/m}
  • Soft Iron (carbonyl, soft) keeps almost nothing: 240 A/m per particle against a saturation of 1700 kA/m — the slug that leaves the coil is nearly blank, at a remanence ratio of 0.00014. A hard particulate is the lever: the remanence of a multi-domain sphere is about three times its coercivity, so a material with a hundred times the coercivity carries a hundred times the magnetisation out of the coil.

Side B, with its numbers

12 A/m=5 %⁢240 A/m
LaTeX 
12\,\mathrm{A/m} = 5\,\mathrm{%} \cdot 240\,\mathrm{A/m}
  • Soft Iron (carbonyl, soft) keeps almost nothing: 240 A/m per particle against a saturation of 1700 kA/m — the slug that leaves the coil is nearly blank, at a remanence ratio of 0.00014. A hard particulate is the lever: the remanence of a multi-domain sphere is about three times its coercivity, so a material with a hundred times the coercivity carries a hundred times the magnetisation out of the coil.