J. Phys. IV France 08 (1998) Pr2-417-Pr2-420
Spin resonance in soft magnetic composite materials : a surprising effect of the magnetic loadA. Chevalier1, F. Le Floc'h2, J.L. Mattei1, Ph. Talbot1 and M. Le Floc'h1
1 LEST, UMR 6616 du CNRS, 6 avenue Le Gorgeu, BP. 809, 29285 Brest cedex, France
2 UMR 652, Chimie-Électrochimie Moléculaire-Chimie Analytique, 6 avenue Le Gorgeu, BP. 809, 29285 Brest cedex, France
The paper shows a successful extension to the high frequencies, namely in the spin resonance regions, of an analytical law firstly proposed to interpret the magnetic properties of soft magnetic composite materials in low fields and in the quasi-static domain. During the first investigations where the frequency did not yet taken into account, it was shown that the effective susceptibility of powder materials was only dependent on three parameters : The magnetic load, the chemical nature of the magnetic compound (through the intrinsic susceptibility) and the internal demagnetizing fields (through the effective shape factor). Dynamic effects were then examined by introducing in the intrinsic susceptibility parameter the dynamic model of Landau and Lifshitz. Experiments carried on soft ferrimagnetic powders (YIG and Ni-Zn spinels) between 10kHz and 20GHz, have led to a total agreement with the analytical law mentioned above.
© EDP Sciences 1998