A Monte Carlo study of the first-order transition in a Heisenberg FCC antiferromagnet

A nearest neighbor Heisenberg antiferromagnet on a face-centered cubic lattice is studied by extensive Monte Carlo simulations in zero magnetic field. The parallel tempering algorithm is utilized, which allows one to overcome a slow relaxation of the magnetic order parameter and to fully equilibrate moderately sized clusters with up to N similar or equal to 7 x 10(3) spins. By collecting energy and order parameter histograms on clusters with up to N similar or equal to 2 x 10(4) sites, we accurately locate the first-order transition point at T-c = 0.4459(1)J. (C) 2005 Pleiades Publishing, Inc.