Neutron Scattering

Fil Schematic illustration of the interaction process of a neutron with the atomic
magnetic moments via the dipole interaction .
This magnetic neutron scattering allows us to study the magnetic properties of a sample on an
atomic level, i . e . with atomic spatial- and atomic energy- resolution . A typical problem
studied is the determination of a magnetic structure, i . e . the magnitudes and arrangements of
the magnetic moments within the sample . Besides the well-known and simple ferromagnets,
for which all moments are parallel, there exists a whole zoo of complicated ferai- and
antifenomagnetic structures, such as helical structures, spin density waves, etc . (compare
figure 3 .8) .
Fil Schematic illustration of the magnetic structures of the hexagonal rare earth
metals. Within the hexagonal basal plane, all moments are parallel. The figure
shows the sequence of moments in successive planes along the hexagonal c-axis .
Besides simple ferromagnetic phases ( , helical (e), conical (d) and c-axismodulated
structures (b) etc. are observed.
3-20