Critical scattering of electrons near the antiferromagnetic transition of TbSb

Precision measurements of the electrical resistance of several TbSb crystals, around their antiferromagnetic transition temperature $T_n=14.5\mathrm{}$ K, are reported. The temperature derivative of the resistance $\frac{\mathrm{dr}}{\mathrm{dT}}$ shows a maximum at $T_n$. Analysis of the data for the term proportional to $t^{-\lambda }$, where $t=\frac{(T-T_n)}{T_n}$ in the region $6\times {10}^{-3\mathrm{}}<\left|t\right|<0.1\mathrm{}$, yields ${\lambda }_{+}=-1.0\mathrm{}$, ${\lambda }_{-}=-1.3\mathrm{}$ for $t$ positive and negative, respectively. This indicates that the spin scattering is dominated by short-range spin correlations. In the same temperature range a smaller exponent of ${\lambda }_{+}\simeq 0.26$, with much larger root-mean-square error, can be obtained if the coefficient of the singular term is constrained to be positive. For $0.1\lesssim t\lesssim 1$, we have ${\lambda }_{+}=1.0\mathrm{}$. The correlation of the resistance derivative with the specific-heat data is investigated and the behavior of the resistance is compared with available theories.