Destruction of first-order phase transition in a random-field Ising model

Abstract

The phase transitions that occur in an infinite-range-interaction Ising ferromagnet in the presence of a double-Gaussian random magnetic field are analyzed. Such random fields are defined as a superposition of two Gaussian distributions, presenting the same width $\sigma$. Is is argued that this distribution is more appropriate for a theoretical description of real systems than its simpler particular cases, i.e., the bimodal ($\sigma =0$) and the single Gaussian distributions. It is shown that a low-temperature first-order phase transition may be destructed for increasing values of $\sigma$, similarly to what happens in the compound $F{e}_{x}M{g}_{1-x}C{l}_2$, whose finite-temperature first-order phase transition is presumably destructed by an increase in the field randomness.

13 pages, 3 figures

Cited by in corpus (3)

• Multicritical Behavior in a Random-Field Ising Model under a Continuous-Field Probability Distribution
• Ising spin glass under continuous-distribution random magnetic fields: Tricritical points and instability lines
• First-order phase transition in a 2D random-field Ising model with conflicting dynamics