A Mössbauer effect study of the magnetic structure of single crystal erbium

Mössbauer effect study of 57Fe in transition metal semiborides and two-dimensional ferrous chloride complexes

“…IY (o) I is the density at the nuclear site of s-electrons with spin Î + 1/2 projections. Generalizing to a multi-electron atom results in the expression for the effective field: Hgff = -Mg I (|Y^S(o)|2 -ly^^(o)f}(22) where the sum is over all s-electrons and |Y^^(o)| is the density at the nuclear site of s-electrons with spin -1/2 projections.In a solid, the magnetic field at the nuclear site will depend on the filling of the relevant electronic shells, and on the inter actions between atoms. In an atom which contains a partially filled magnetic shell such as the 3d-shell of iron, the interaction between the spin up polarized 3d shell and a spin up s-electron Is attractive, while the same interaction with a spin down s-electron is repulsive.Therefore, even in filled s-shells, differences in spin up and spin down electron densities can exist.The existence of this difference in electron density between the spin up and spin down case means that even for paired s-electrons is not necessarily zero.…”