Static Magnetic Susceptibility of Si : P across the Metal-Insulator Transition

The static magnetic susceptibility of phosphorus doped silicon is measured over the temperature range from 10 mK to 4.2 K at phosphorus concentrations from 5.3×10 17 to 2.8×10 19 cm -3 . The paramagnetic deviation of susceptibility is observed for samples N ≤4.5×10 18 cm -3 at low temperatures and the donor susceptibility χ D varies continuously across the metal-insulator transition. The temperature dependence of χ D is roughly described by T - a law for the lightly metallic samples as well as for the non-metallic ones. The results are discussed in connection with the theories and the experiments of ESR and specific heat.