Critical resistivity of antiferromagnetic semiconductors

The resistivity of nearly stoichiometric iron oxide was measured in the temperature range 78<~T<~300°K. The temperature derivative of the resistivity, dρdT, in the vicinity of the critical temperature, Tc, was found to be proportional to ε-0.4, where ε=|(T-Tc)Tc|. The results are explained by incorporating a normalized Ornstein-Zernike correlation function into the de Gennes-Friedel formula for critical scattering.