Abstract
© 2022 Elsevier B.V.Ising-like model of the spin-crossover solids is studied making use of thermodynamic geometry in the Ruppeiner formalism. A thermal metric tensor (Gij) and corresponding thermodynamic curvature or Ricci scalar (R) are computed for a 2D “magnatization” vs “temperature” state space. The two metric components, namely G12 and G22, have the finite extremum above the critical temperature in the high-spin state. On the other hand, R abruptly jumps between the R>0 and R<0 regions along the first-order high-spin/low-spin transition line while the curvature jump disappears when the critical point (C) is reached. It exhibits smooth changes beyond C along the R=0 line. A different vanishing curvature line with R=0 is also observed in the high-spin state regime in the geometric phase diagram.
NSTL