Magnetic ordering in two ferromagnetic sublattices of two mixed-valence iron(II)-iron(III) metal formate frameworks

Temperature dependence of magnetization (M) is calculated for two mixed-valence iron(II) - iron(III) metal formate frameworks (MOFs) with the two ferromagnetic sublattices below T-comp (compensation temperature) at 100 Oe by the molecular field theory. Temperature dependence of magnetization (M-T) is analyzed between T(comp )and T-ord = 39K (ordering temperature) by the power-law formula using the literature data for those compounds. Power-law analysis is also carried out for the field dependence of magnetization (M-H) for 0 < H < 50 Oe interval (T = 2 K) by using the literature data for those MOFs. From both power-law analyses, the temperature-induced (beta) and field-induced (delta) critical exponents for magnetization are deduced for the compounds studied.


Magnetic transitions in two novel mixed-valence iron(II)–iron(III) metal formate frameworks: Two sublattice model
Yurtseven, Hasan Hamit; Tari, O. (2022-03-15)
We study the two-sublattice model in the mean field theory by expanding the Gibbs free energy in terms of the magnetizations M1 (Mup) and M2 (Mdown) with the quadratic coupling M12M22 (quadrupolar interactions) for the order–disorder transition in the two mixed-valence iron (II)-iron (III) metal formate frameworks, C2H5NH3FeIIFeIIIHCOO6 and C2H52NH2FeIIFeIIIHCOO6. Expressions derived from the Gibbs free energy for the temperature dependence of the magnetizations M1 and M2, are fitted to the observed data (H...
Magnetization Studied as a Function of Temperature and Magnetic Field for Ferromagnetic Transition in DMNaFe
Kilit Dogan, E.; Yurtseven, Hasan Hamit (Springer Science and Business Media LLC, 2020-08-01)
Magnetization has been calculated as a function of temperature in the ferromagnetic phase of (CH3)(2)NH2Na0.5Fe0.5(HCOO)(3)denoted by DMNaFe as one of the metal formate framework by using molecular field theory. CalculatedM(T) is compared with the magnetization measured as a function of temperature (H = 10 Oe) in field-cooling and zero-field-cooling regimes from the literature, and a power-law analysis of the experimental data was performed for DMNaFe. Magnetization measured as a function of the magnetic fi...
Optical properties of Tl2InGaS4 layered single crystal
Qasrawi, A. F.; Hasanlı, Nızamı (Elsevier BV, 2007-08-01)
The temperature dependence of the optical band gap of Tl2InGaS4 single crystal in the temperature region of 300-500 K and the room temperature refractive index, n(lambda), have been investigated. The absorption coefficient, which was calculated from the transmittance and reflectance spectra in the incident photon energy range of 2.28-2.48 eV, increased with increasing temperature. Consistently, the absorption edge shifts to lower energy values as temperature increases. The fundamental absorption edge corres...
Calculation of the Ν4 (NH4) IR Mode Frequency and the Damping Constant (FWHM) Close to the Phase Transitions in NH4Zn(HCOO)3 and Nd4Zn(DCOO)3
Kurt, Arzu; Yurtseven, Hasan Hamit; Kurt, Mustafa (2018-09-09)
Temperature dependence of the IR frequency and the damping constant (FWHM) of the ν4(1440 cm-1) NH4+and ν4(1084 cm-1) ND4+ modes, are calculated for the metal formate frameworks (MOFs) of NH4Zn(HCOO)3 and ND4Zn(DCOO)3, respectively, by using the experimental data from the literature. By assuming the IR frequency of the ν4 mode as an order parameter, its temperature dependence is calculated close to the phase transition (TC=191 K) in the NH4Zn(HCOO)3 and ND4Zn(DCOO)3 by the molecular field theory. The temper...
Critical behaviour of ammonia near the melting point
Yurtseven, Hasan Hamit (2002-08-01)
This study gives our calculations for thermodynamic quantities, such as the isothermal cornpressibility k(T), thermal expansivity alphap and the specific heat C-P, as a function of temperature for solid ammonia near the melting point. Our calculations, which have been performed on the basis of an experimental study given in the literature, show that those thermodynamic quantities diver e near the melting point in ammonia. This is an indication that ammonia exhibits a critical transition as one approaches th...
Citation Formats
H. H. Yurtseven, “Magnetic ordering in two ferromagnetic sublattices of two mixed-valence iron(II)-iron(III) metal formate frameworks,” MATERIALS RESEARCH BULLETIN, pp. 0–0, 2019, Accessed: 00, 2020. [Online]. Available: