Axial ZFS parameter

Also, the heat capacity is affected by the axial ZFS parameter and, in excess of the lattice contribution, it shows a Schottky anomaly as modeled in Fig. 2. In the zero magnetic field the isofield heat capacity Ch collapses to the usual Cp and stays isotropic. 

The SH formalism offers a simple formula for the axial ZFS parameter ... 

Fig. 1.17. The splitting of an S = 1 (A) and S = % (B) manifold in the presence of spin orbit coupling and low symmetry components. D is the axial and E the rhombic ZFS parameter (the latter only shown in case A). The wavefunctions are labeled as high field eigenfunctions.

In the case of the 5 = 5/2 ground states of high-spin Fe complexes, there is a ZFS of the Ms = 1/2, 3/2, 5/2 microstates due to spin-orbit coupling based on the axial D) and rhombic E) ZFS parameters within the spin Hamiltonian, H, with the central metal (Figure 13) and equation (22) ... 

Molecular g value (g), axial (D) and rhombic ( ) zero field splitting (ZFS) parameters, exchange interaction (J)... 

In Equation (2), D and E are the axial and rhombic zero-field splitting (ZFS) parameters, respectively, and g is the electronic g tensor. The magnetic hyperfine interactions of the electronic system with the Fe nucleus are described by S-a-I, and —is the nuclear Zeeman term. The quadrupole interaction involves the traceless EFG tensor. The EFG tensor has principal components Vyy, and The asymmetry parameter t] = Vxx- VyyyiV can be confined to 0 < 7 < 1 if the convention V zl > I Vyy > V xl is adopted. A quadrupole doublet... 

Here, D and E are the axial and rhombic ZFS parameters, respectively. Application of Equation (8) to the spin functions 5, Mf) with 5=3/2 results in a fourth order equation, which describes the behavior of the four energy levels in Figure 3b as a function of the magnitude of the external field and its orientation relative to the molecular frame. For an exact solution for the spin Hamiltonian the 4x4 matrix must be diagonalized at every field. For Kramer ions the parameters D and E can generally be determined by EPR spectroscopy. 

If D is taken as a traceless tensor, Tr(/)) = Da = 0, there remain only two independent components for D (neglecting the three Euler angles for orientation in a general coordinate system). Usually, these are the parameters D and E, for the axial and rhombic contribution to the ZFS ... 

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