Finite-size scaling in a two-dimensional randomly coupled Ising ferromagnet

It is shown by using a Monte Carlo method that finite-size scaling (FSS) holds in a two-dimensional randomly coupled Ising ferromagnet. It is also demonstrated that the form of the universal FSS function constructed via a novel FSS scheme depends on the strength of the random coupling for strongly disordered cases. Monte Carlo measurements of the thermodynamic data (infinite-volume limit data) for correlation lengths (xi) up to xi similar or equal to 200 are reported and analyzed in view of two competing scenarios. It is argued that the data are almost exclusively consistent with the scenario of weak universality.