We studied the weak field Hall voltage in 2D electron layers in Si-MOS structures with different mobilities, through the metal-insulator transition. In the vicinity of the critical density on the metallic side of the transition, we have found weak deviations (about 6-20 %) of the Hall voltage from its classical value. The deviations do not correlate with the strong temperature dependence of the diagonal resistivity rho_{xx}(T). The smallest deviation in R_{xy} was found in the highest mobility sample exhibiting the largest variation in the diagonal resistivity \rho_{xx} with temperature (by a factor of 5).
@article{arxiv.cond-mat/9904233,
title = {Weak Field Hall Resistance and Effective Carrier Density Through Metal-Insulator Transition in Si-MOS Structures},
author = {V. M. Pudalov and G. Brunthaler and A. Prinz and G. Bauer},
journal= {arXiv preprint arXiv:cond-mat/9904233},
year = {2009}
}