Influence of V and Mn doping on the electrical transport properties of a Cr + 1.2 at.% Ga alloy

Measurements of the electrical resistivity (ρ) of a Cr + 1.2 at.% Ga alloy doped with V or Mn, are reported in the temperature range 6-900 K. These measurements were complimented with thermal expansion (α) measurements for the undoped Cr + 1.2 at.% Ga alloy in the temperature range 77-450 K. The measurements show interesting behaviour with dopant concentration in that the residual resistivity (ρ_residual) does not vary smoothly with dopant concentration as expected. On the contrary, ρ_residual shows three peaks as a function of dopant concentration. This behaviour is ascribed to impurity resonant scattering effects which are included in a theoretical model used to explain the observed temperature dependence of the resistivity for these alloys. The resistivity and thermal expansion coefficient of the Cr + 1.2 at.% Ga alloy behaves anomalously close to the ISDW-CSDW phase transition temperature (T_IC). The temperature derivative of the resistivity shows a minimum while the α-T curve shows a peak at T _IC in contrast to what is expected. The magnetic phase diagram of the (Cr + 1.2 at.% Ga)(V, Mn) alloy system is constructed from the results of the measurements.