Metallization and superconductivity in CsI at pressures up to 220 GPa

The pressure range for electrical transport measurements has been dramatically increased up to 220 GPa in the 0.05-300 K temperature region and at magnetic fields of up to 10 T. Metallization of caesium iodide was found at a pressure of 115 GPa. A superconducting transition with was observed above 180 GPa. decreases with increasing pressure. The superconducting transition shifts to lower temperatures and disappears under magnetic field above 0.3 Tesla.