Disorder-induced resistive anomaly near ferromagnetic phase transitions.
We show that the resistivity rho(T) of disordered ferromagnets near, and above, the Curie temperature T(c) generically exhibits a stronger anomaly than the scaling-based Fisher-Langer prediction. Treating transport beyond the Boltzmann description, we find that within mean-field theory, drho/dT exhibits a |T - T(c)|(-1/2) singularity near T(c). Our results, being solely due to impurities, are relevant to ferromagnets with low T(c), such as SrRuO(3) or diluted magnetic semiconductors, whose mobility near T(c) is limited by disorder.
Timm
Carsten
C
Institut für Theoretische Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany.
Raikh
M E
ME
von Oppen
Felix
F