The critical resistivity of an antiferromagnetic metal

The critical resistivity is analysed in detail for the first time and is found to yield a critical amplitude ratio as well as critical exponents. Thus, critical resistivity is shown to be a helpful tool for the determination of critical parameters. In the present analysis, the published data of Rao and coworkers on the resistivity of dysprosium are used. The results indicate that the critical resistivity of this material has a magnetic energy-like temperature dependence, both above and below the critical point, T_c. Since antiferromagnetic metals belong to the only class of materials for which this universal dependence of the resistivity was questioned, the present results, as well as theoretical considerations given here, establish this universality. The specific heat critical parameters obtained here, α = α′ = -0.04 ± 0.005 and |A/A′| = 1.44 ± 0.05, are the only critical parameters obtained thus far for dysprosium, which were shown to be temperature independent over two orders of magnitude of the reduced temperature t (3 × 10^-4 ≤|t| ≤ 3 × 10^-2). The deviation of the above values from the theoretical predictions for the ε{lunate} = 1, n = 4 model may be attributed to the low accuraacy of the ε{lunate}-expansion as well as to the special properties of the magnetic interactions in dysprosium.