Dear Alan,
I succeeded in opening your Mathcad file. Thank you!
I looked through your file and in the last expression, that for Mtotal, I changed (sin(alpha_i) + sin(phi_i) to (sin(alpha_i+phi_i)) and immediately got the expected result. It is correct in a sense that the low-field magnetization is (MEr-MCo) = 9 - 5 = 4 (magnetic moments are antiparallel), and the high field magnetization is (MEr + MCo) = 9 + 5 = 14 (magnetic moments are parallel). Moreover, the overall shape of the curve is correct: linear section -> slanted section -> linear section.
I've attached your file with the modified formula for Mtotal and an increased range of B values, 0...200, just to see the whole magnetization process.
From your file it is clear to me that I should learn to use solve blocks to do this sort of calculations. Well, at least I know what my problem is.
Thank you.
Regards,
Den