Scaling behavior of the Hall coefficient of Si:P at the metal-insulator transition

Abstract

Measurements of the Hall coefficient RH(T, B) of Si:P with P concentration N between 3.54 and 7.0·1018 cm−3 are reported for the temperature range 0.04 K ≤ T ≤ 4K and in magnetic fields up to 7 T. Even far above the metal-insulator transition (MIT), a sign change of the temperature coefficient similar to the behavior of the conductivity σ(T) in moderate fields is not observed in RH(T). Field and temperature dependence of RH both increase as the MIT (at the critical concentration Nc = 3.52 · 1018 cm−3) is approached. A careful extrapolation to T → 0 and B → 0 indicates that RH−1 scales to zero as RH−1 ∼| N − NcμH with μH = (0.44 ± 0.04) in agreement with previous results.