Aspects on the critical behaviour of transport properties in ferromagnetic metals

New experimental results are presented to extend information into less well known aspects concerning the behaviour of transport properties in ferromagnetic systems. We study in particular the critical behaviour of the temperature derivative of the electrical resistivity (dϱ/dT) in the vicinity of a spin-reorientation transition (Ts). In addition, the extreme sensitivity of dϱ/dT is used to investigate the role of magnetic domains in the vicinity of a ferro-paramagnetic phase transition (Tc).