Research Information System
European Physical Journal Plus, vol.138, no.4, 2023 (SCI-Expanded)
We present an approach to analyze the equilibrium states in a spin-1 Ising model with bilinear and biquadratic interactions using mean (H) and Gaussian (K) curvatures of the mean-field free energy surface. From the temperature variation of H and K, we have reported the local shapes of equilibrium free energies for the paramagnetic, ferromagnetic and quadrupolar solutions. It is important to mention that a minimal surface for the paramagnetic case with H= 0 , K< 0 is explicitly observed. For the ferromagnetic case, it is found that the curvature H displays a cusp singularity at the criticality with the exponent values of (λH,λH′)=(0,1) and a convergence of K is observed with λK= 1.0.