[17] A new approach to critical exponent in phase-transitions of spin-systems

We investigate an alternative approach to obtain critical exponents from standard numerical simulations of spin-systems avoiding the commonly used finite size scaling technique. We show that by analyzing the inverse logarithmic derivative of the susceptibility $\chi$ with respect to temperature instead of the susceptibility directly the accuracy and efficiency of determining the exponent $\gamma$ can be increased by at least one order of magnitude. The two dimensional Ising model is used for a test, but this direct approach should be useful for spin systems on nonperiodic structures like quasi--crystals and fractals where finite size scaling has difficulties.