Weak-field Hall resistance and effective carrier density measurements across the metal-insulator transition in Si-MOS structures

The weak-field Hall voltage in Si-MOS structures with different mobility is studied on both sides of the metal-insulator transition. In the vicinity o f the critical density on the metallic side of the transition, the Hall vol tage is found to deviate by 6-20 % from its classical value. The deviation does not correlate with the strong temperature dependence of the diagonal r esistivity rho(xx)(T). In particular, the smallest deviation in R-xy is fou nd in the highest-mobility sample, which exhibits the largest variation in the diagonal resistivity rho(xx) with temperature. (C) 1999 American Instit ute of Physics. [S0021-3640(99)00913-5].