Complex transverse susceptibility is a recent proposed method for the determination of anisotropy and volume distributions in particulate magnetic media. So far, only thermal fluctuations and rate-dependent damped dynamics of the magnetic moment have been identified as reasons for the existence of the imaginary transverse susceptibility. In this paper, we apply a more general approach to derive the complex transverse susceptibility, and we show that the hysteresis phenomenon is the most general concept behind the existence of complex transverse susceptibility. In this paper, the physical origins of the imaginary part of transverse susceptibility are analyzed: rate-independent hysteresis, viscous-type rate-dependent hysteresis, and thermal relaxation effect origin. The rate-independent origin is an intrinsic contribution to the imaginary transverse susceptibility and cannot be neglected because it is a zero-temperature effect.
Physical Review B
Phys. Rev. B 76, 054409 (2007)