Phase transition properties of the Bell-Lavis model

Area of Science:

• Statistical Mechanics
• Condensed Matter Physics
• Computational Physics

Background:

• The study investigates phase transitions in a triangular antiferromagnetic three-state Bell-Lavis model.
• Understanding the order and universality classes of these transitions is crucial for characterizing complex magnetic systems.

Purpose of the Study:

• To analyze the order and universality class of phase transitions into the low-density honeycomb phase.
• To determine the behavior of these transitions across a range of chemical potentials.
• To compare the model's behavior with related models like the Blume-Capel model.

Main Methods:

• Utilizing Monte Carlo calculations to simulate the model.
• Analyzing the behavior of the system across a range of chemical potentials (μ).
• Identifying the universality class of the observed phase transitions.

Main Results:

• Phase transitions are primarily attributed to the three-state Potts universality class for most chemical potentials.
• Transitions become first-order at the boundary between the honeycomb and low-density gas phases.
• A crossover from three-state Potts to Ising universality class is observed at the honeycomb-to-frustrated phase boundary.
• A Schottky anomaly in specific heat is detected near this boundary.
• The intermediate planar phase observed in the Blume-Capel model is absent in the Bell-Lavis model.

Conclusions:

• The Bell-Lavis model exhibits complex phase transition behavior, predominantly following the three-state Potts universality class.
• Specific phase boundaries lead to deviations, including first-order transitions and crossovers to Ising universality.
• The absence of an intermediate planar phase distinguishes it from the similar Blume-Capel model.