The Influence of Antiferromagnetic Order on the Evaluation of Spin Disorder Resistivity

It is known that the parameters ϱ spd (spin disorder rosistivity) and θ p can be used for estimating the effective mass m* of the conduction electrons and exchange constant G. ϱ spd is the temperature independent contribution to the electrical resistivity in the paramagnetic temperature range whereby this contribution is due to the disordered localized spins, and θ p is the paramagnetic Curie temperature. The above procedure is appeared in the literature for the rare earth melalv (R) and their interinetallic compounds not only for ferromagnetic (Ral 2 ) but also for antiferromagnetic (Rau 2 , Rag 2 , Rcu 2 ) systems. It is tested whether such a procedure for estimating m * and G is valid irrespective of whether the ordering is ferromagnetic or antifcrromagnctic. This investigation is carried out for the system Gd(Ni, CU) 2 and it is shown that the above procedure is principally inapplicable for θ spd i values obtained from antiferromagnctic samples. In addition a discussion is given of the validity of the free electron approximation in the Gd(Ni, Cu) 2 and the GdZn 2 systems, whereby it is concluded that the s‐character deteriorates with increasing electron concentration.