Finite size effects on measures of critical exponents in d = 3 O(N) models

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.