Observation of an itinerant metamagnetic transition in MnSi under high pressure

Magnetization measurements have been performed on single-crystalline MnSi under high pressures up to 1.54 GPa and high magnetic fields up to 10 T in the temperature range from 1.7 to 60 K. The magnetization process exhibits no hysteresis in the pressure region up to 1.34 GPa. At $P=1.54\mathrm{}\mathrm{GPa},$ we have clearly observed a metamagnetic transition around $B=0.1\mathrm{}\mathrm{T}$ with hysteresis in the magnetization process at low temperatures below 6 K. From the experimental results, we have determined the magnetic phase diagram of MnSi for $P=1.54\mathrm{}\mathrm{GPa}.$