FERROMAGNETIC TRANSITION OF + -J ISING SPIN-GLASS MODEL ON SQUARE LATTICE/

The ferromagnetic transition of +/-J-Ising spin-glass model on square lattice is studied by using Monte Carlo simulation. At ferromagnetic-b ond density p = 0.96 where the system shows ferromagnetic transition, the spontaneous magnetization, the ratio [m(4)]/[m(2)](2) and the none quilibrium relaxation (NER) are studied. The transition is estimated t o he at K-c = 0.5100(1). The analysis by NER gives the most reliable e stimation with the least CPU time for simulations among the three meth ods. The value of magnetization exponent beta is estimated to he 0.130 (10) which coincides with that of the purely ferromagnetic Ising model (p = 1). The dynamical critical exponent 2 is estimated to be 2.418(2 3) from the NER analysis which is different from that of the pure mode l. The size of simulated lattices is up to 2001 x 2000, and the number of totally updated Ising spins is 5.5 x 10(15).