AbstractThe properties of a two‐dimensional electronic system in n‐inversion layers in grain boundaries of p‐InSb bicrystals are investigated under high hydrostatic pressure (up to 103MPa) in high magnetic fields (up to 14 T). A rapid decrease of the carrier concentration in the inversion layer is observed when hydrostatic pressure is applied. At high pressures and high magnetic fields it is experimentally verified that the Hall resistivity ϱxyis quantized into integer multiplies