On the tricritical point in MnSi under high pressures

The magnetic susceptibility of a MnSi single crystal is measured in the region of the ferromagnetic phase transition under pressures up to 0.8 GPa in compressed helium. It is found that the tricritical point on the phase-transition curve corresponds to a much lower pressure and a considerably higher temperature (P _tr ≈ 0.355 GPa and T _tr ≈ 25.2 K) than was reported earlier (P _tr ≈ 1.2 GPa and T _tr ≈ 12 K). New results impose certain limitations on theoretical analysis of tricritical phenomena in MnSi.