Abstract:
Abstract An investigation into the physical properties of Cr100-xIrx alloy single crystals, with x = 0.7, 1.5, 2.0 and 2.5, were previously used to determine the magnetic phase diagram of Cr100-xIrx alloy system around triple point concentration [1] where the various magnetic phases co-exist. The present study extends these results by considering the temperature (T) dependence of the Seebeck coefficient (S), specific heat (Cp) and Hall coefficient (RH) measurements, in addition to the electrical resistivity (ρ) (also measured previously). Well defined anomalies were observed in the electrical resistivity ρ(T) curves of all the samples, due to the antiferromagnetic to paramagnetic phase transition at the Néel temperature (TN). The S(T) curves of the samples with x = 0.7, 1.5 and 2.0 also exhibit anomalies associated with TN in the temperature range below 380 K. However, for x = 2.5 with TN = 391.5 K [1] no such anomaly is observed as the present measurements could only be done for 2 K ≤ T ≤ 380 K. Contrary to what is normally expected [2] it is noted that the anomaly related to TN is more prominent in the ρ(T) curves than in the S(T) curves. RH measurements, carried out from 380 K down to 2 K in a constant magnetic field of 6 T, shows only weak anomalies at TN for certain of the samples. The Sommerfeld coefficient (γ) is obtained by fitting Cp/T to the low temperature Cp/T versus T^2 data. The γ values found for the present single crystal samples fits in well with the γ versus electron-to-atom (e/a) ratio curve previously published for certain Cr alloys