Low-field magnetic hysteresis in gadolinium and terbium

Abstract

The Fourier components of the ferromagnetic hysteresis of polycrystalline gadolinium and terbium have been measured in low ac magnetic fields (0.1–15 A m−1) using synchronous detection. The field dependences and magnitudes of the various harmonics cannot be described by the Rayleigh hysteresis law. It is shown that the dominant term in the absorptive component of the first harmonic is associated with a magnetic aftereffect. At the lowest fields (H≲1 A m−1) there are indications that magnetic hysteresis vanishes.