Investigation of fundamental and higher harmonics of ac susceptibility under general field direction: Effects of field and sample geometry

Behaviour of fundamental and higher harmonics of ac susceptibility is studied for cylindrical geometry subjected to an applied ac field B = Baccos(ωt) along any arbitrary direction with respect to the cylinder axis. Variations of the parallel and two perpendicular in-phase (χ′) and out-of-phase (χ″) ac susceptibility components are investigated in details with respect to the change in the applied field geometry (field orientations and amplitudes). The effects of geometrical anisotropy of the sample on the ac susceptibility measurements are also discussed. Some of our selected results compares well with the experimental studies.