Question

What is ion quadrupole interactions?

Answer 1

Explanation:

Electric Quadrupole Splitting

Electric quadrupole interaction is related to the orientation of non-spherical nuclei in the inhomogeneous electric field generated by an asymmetric charge distribution of the surrounding electrons. The resulting hyperfine coupling energy depends on the nuclear quadrupole moment and the electric field gradient (efg) generated by the electrons. Only nuclei with spin I > 1/2 are subjected to quadrupole interaction, because others do not have a quadrupole moment. Thus, the ground state of 57Fe is not affected, but the excited state is split into a two Kramers doublets with magnetic quantum numbers mI = ±1/2 and ±3/2. (Figure 5.7, top middle; the reader may note the similarity of nuclear quadrupole splitting and zero-field splitting in the electric shell for S = 3/2 systems). Therefore, two γ-transitions are possible for 57Fe with electric quadrupole interaction, the energy difference of which is seen as quadrupole splitting ΔEQ of the resulting spectrum.

The efg is a traceless tensor a (ΣVii = 0, see Figure 5.9) with only two independent components in the principal axes system. Usually, the so-called main component Vzz and the asymmetry parameter η = (Vxx − Vyy)/Vzz are selected as independent parameters. The range of η can be restricted to 0 ≤ η ≤ 1, since the tensor axes are selected such that Vzz is the largest component. For 57Fe, the quadrupole splitting is given by the relation ΔEQ=1/2·eQVzz1+η2/3, where eQVzz is called the quadrupole coupling constant. The main component of the efg may be positive or negative, depending on the type of asymmetry of the electronic charge distribution that causes the efg (see Figure 5.9, right). Next, we will discuss some archetypical charge distributions in the valence shell that cause an efg at the Mössbauer nucleus.

Answer 2

Answer:

Electric quadrupole interaction is related to the orientation of non-spherical nuclei in the inhomogeneous electric field generated by an asymmetric charge distribution of the surrounding electrons.

Explanation: