Phase Transition Behaviour of Ising Spin Glass on the FCC Lattice

Abstract

In this work, we study the nature of phase transition in a face centered cubic (FCC) antiferromagnet with Ising spins. The spin-glass character depends on the concentration $p$ of ferromagnetic bonds randomly generated into the system. We introduce a new quantity $M_Q$ combined by the Edwards-Anderson order parameter $Q$ and the standard magnetization $M$. Note that, it is impossible to obtain the susceptibility defined by the variance of $Q$ or $M$, but we can do that for $M_Q$. Using the standard Monte-Carlo and powerful Wang-Landau flat-histogram methods, we carry out in this work intensive simulations with many value of $p$. We show that the first-order transition has been destroyed with a tiny amount of ferromagnetic bond $p\sim 0.01$. With increasing $p$, the antiferromagnetic phase changes into a spin glass, and then to ferromagnetic phase.