Neutron Scattering

; '
.
r,°'r,
Figure 17 Crystal field scheme and measured energy scans in PrB3 (T=1 .5 K), frorn reference [6] .
group by F i .
In close resemblance to equations (13 .10) and (13 .24) the differential cross
section arises from the sum of transition probabilities F i ---> F j ; these matrix elements
may be calculated within point charge models .
13.4 Conclusions
Inelastic neutron scattering is almost the unique technique to observe lattice vibrations
and magnetic excitations throughout the whole Brillouin-zone .
The main part of our
knowledge on these topics has indeed been achieved by neutron studies .
Also the subjects of present interest, like high-T, superconductors, heavy fermions,
quasi-crystals,
C60 and compounds with colossal magneto-resistivity demand a detailed
analysis of their lattice dynamics as well as of their magnetism .
Frequently the materials
of current interest exhibit a large complexity ;
therefore their study requires a continuons
development of the experimental facilities as well as of the analysis methods .
References
1 N .W . Ashcroft and N.D . Mermin, Solid State Physics, Holt-Saunders International
Editions, Philadelphia (1976) .
13-25