Question

What's “the” physical explanation of hysteresis in ferrimagnetic materials?

Answer 1

I am wondering what is "the" or "a" physical explanation of hysteresis in ferrimagnetic materials.

From what I've read in wikipedia and Cullity's book, there is a simple physical explanation for ferromagnetic materials's hysteresis while it is said that ferrimagnetic materials also exhibit hysteresis while the physical explanation is omitted. Basically a ferromagnetic material contains domains where the moments of atoms point roughly in the same direction, but the domains's moments point in random directions so that at first the material has no net magnetization. When a magnetic field is applied, the domain walls move so that the net magnetic moment of the whole material increases and tends to point in the same direction than the applied field. But this can't hold true for any value of applied field, indeed at some point the walls have almost vanished (or can't move anymore due to impurities, etc.). Then what happens is that the magnetization of the domain(s) rotates toward the applied field, eventually reaching the saturation magnetization for some value of the applied field from which the magnetization of the material almost doesn't increase even though the applied field continues to increase.

But in the case of ferrimagnetic materals, there is no magnetic domains. Instead, at a microscopic level (at least in ferrites) there are A and B sites which form A and B alternating sublattices. Where the magnetic moments of the A and B sublattices are different, hence the material showing a non zero magnetization even in the absence of applied field. I can't seem to be able to apply any of the 2 mechanisms (walls motion and rotation) that makes a ferrogmatic material display hysteresis. Hence my title question

Answer 2

ferromagnetic materials is answer..