Calculation of the thermodynamic quantities of perovskite metal organics DMAKCr and perovskite HyFe close to the weakly first-order relaxor-like structural transformation using the mean field theory

Yurtseven H., Tari O.

INTERNATIONAL JOURNAL OF MODERN PHYSICS B, vol.33, no.11, 2019 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 33 Issue: 11
  • Publication Date: 2019
  • Doi Number: 10.1142/s0217979219501030
  • Journal Name: INTERNATIONAL JOURNAL OF MODERN PHYSICS B
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Keywords: Thermodynamic quantities, weakly first-order transition, mean field theory, DMAKCr, perovskite HyFe, MAGNETIC ENTROPY CHANGE, PHASE-TRANSITIONS, FORMATE FRAMEWORKS, DIELECTRIC ANOMALIES, PHONON PROPERTIES, M-II, FE, TEMPERATURE, MN, NI
  • Middle East Technical University Affiliated: Yes

Abstract

Weakly first-order or nearly second-order phase transitions occurring in metal{organic frameworks (MOFs), particularly in DMAKCr and perovskite HyFe, are studied under the mean field model by using the observed data from the literature. In this work, mainly thermal and magnetic properties among various physical properties which have been reported in the literature for those MOFs are studied by the mean field theory. By expanding the free energy in terms of the magnetization (order parameter), the excess heat capacity (Delta C-P) and entropy (Delta S), latent heat (L), magnetization (M) and the inverse susceptibility (chi(-1)) are calculated as a function of temperature close to the weakly first-order phase transition within the Landau phenomenological model which is fitted to the experimental data from the literature for C-P (DMAKCr and perovskite HyFe) and for magnetization M (HyFe).