ferrite or just steel for low B

[BobM3]

For a torodial core in which I'm looking for a B max of maybe 60mT and I'm not looking for high frequency performance is there a need to use ferrite? I'm not really concerned about losses - just looking for something fairly linear (BH curve) for low values of B. I'm thinking steel would be fine but I can't find data on how linear it is with small flux densities.

 

[MagMike]

Steel would be good at producing the flux you are looking for but is highly non-linear. So the question becomes one of how linear does it have to be? By linear, do you mean reversible or non-hysteretic?

Most books on magnetics should have a BH curve for steel at low values of B.

 

[EdStainless]

I believe that some of the powdered Fe core materials would be more linear than common steels, but nothing like ferrite. Maybe a 'bad' ferrite would be good enough for htis application.

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