Theory of Transition Ion Complexes

Abstract

It is suggested that the observed lowering of the spin-orbit parameters in transition-ion complexes is caused by a screening effect which expands the 3d wave functions. Evidence in support of this suggestion is given by neutron diffraction form-factor measurements on Mn ++ salts. The theory of the transferred hyperfine interaction between the electron spin of Mn ++ and surrounding F 19 nuclei is discussed, and the complications introduced into the theory when dealing with other ions are described. The theory is found to be unsatisfactory because it is not possible to treat the interaction via the Is orbitals of F" with sufficient accuracy.

Calculation of the g‐shift and superhyperfine structure tensor of Mn2+ ion in AIIBVI tetrahedral semiconductors

“…Unfortunately, in the spin-neglecting scattered-wave calculations we cannot obtain terms not equal to zero, deriving from core orbitals. These terms, particularly the cross terms between s-core orbitals may be large, as was pointed out by Marshall [23], but it is a rather unexpected effect. On the other hand, in the scattered wave calculations we obtain "proper" spin densities and no free atom or ion spin densities as in LCAO calculations.…”

Nuclear Magnetic Resonance in Ferromagnets and Antiferromagnets

“…. ., 9) sublattice AMp(T) has the form where Hp is the effective field for the pth sublattice. The index v characterizes the type of spin wave branch.…”

On the effect of overlapping and covalency on the optical spectra of impurity ions in dielectric crystals

“…The authors of [l] and [3] attributed this effect to the radial expansion of 3d-functions, which is connected with the screening of the nucleus by the electron ligand shells. However?…”

“…Assuming N y 1 / 2 = 1 -2 , the authors of [2] obtain "variable [3,5], since the overlapping with the ligand shells is sometimes significant. We proposed in [9,10] to take into account the effect of the molecular bonding of the impurity and the ligand ions (in MO-LCAO form) on the NEF in the same way as it is performed in C F parameter calculations (see the review of articles in [12]).…”