We study the critical properties of three-dimensional O(N) models, for
N=2,3,4. Parameterizing the leading corrections-to-scaling for the η
exponent, we obtain a reliable infinite volume extrapolation, incompatible with
previous Monte Carlo values, but in agreement with ϵ-expansions. We
also measure the critical exponent related with the tensorial magnetization as
well as the ν exponents and critical couplings.Comment: 12 pages, 2 postscript figure