Physical properties and magnetic phase diagram of (Cr₉₀Ir₁₀)_100-yV_y alloy system

The magnetic phase diagram of (Cr₉₀Ir₁₀)_100-yV_y alloy system has been constructed using the T_N values obtained from the electrical resistivity, ρ, Seebeck coefficient, S, and magnetization, M, as function of temperature measurements. The present study furthermore proposes a V induced commensurate (C) spin-density-wave (SDW) to incommensurate (I) SDW phase transition on cooling, at a transition temperature T_CI, in certain samples in the series investigated. MT measurements on the sample with y = 2.4 shows only one transition associated with the Néel transition at T_N, with no additional transition that can be associated with T_CI and is accepted to be in the CSDW phase at all temperatures. It is hypothesized that the addition of V destabilizes the CSDW phase and introduces an ISDW phase at lower temperatures in the samples with y = 3.4, y = 3.6 and y = 5.4, as the χ(T) curves of these samples show two transitions. It is suggested that all the samples with y ≤ 5.4 show magnetic phase transitions at T_N on cooling from the paramagnetic (PM) to CSDW phase. On further addition of V the samples with y > 5.4 the obtained χ(T) curves show only one transition that suggest that these samples are in the ISDW phase at all temperatures below T_N. Results suggest a quantum critical behavior at V concentration of y_c = 9.033.