Magnetic Ordering in the three-dimensional frustrated Heisenberg model

Monte Carlo simulations of moderately frustrated three-dimensional Heisenberg spin systems show evidence for two distinct ordering events. The upper one, at Tc, marks the onset of long-range ferromagnetic order and exhibits fluctuations which scale as the system size. The lower event, at Txy, marks the freezing of transverse degrees of freedom and does not affect the long-range order in the system. Critical levels of frustration for the onset of ferromagnetism have been determined on several lattices and a phase diagram is presente