1 - IAEA Nuclear Data Services

- 121 -
The latter result shows a striking fine structure in the otherwise
smooth empirical function of Zp versus mass number and is probably
caused "by the closed shell of 50 neutrons.
2.3- Publications
P. del Marmol and M. ÎTève de Mévergnies, J. Inorg. ITucl. Chem.
12; (1967) 273
P. ael Marmol, Arkiv fbr Pysik, ¿6 (1967) 205
3 • Inelastic Scattering of Slow ITeutrons
S. ÏÏAUTECLER
In order to explain the lattice dynamics of bcc and fee metals,
KEEBS has developed a force model in which the metal is considered
as a lattice of spherical ions, of uniform charge distribution,
embedded in an electron sea. The physical content of this model
has been applied to the case of hexagonal close-packed metals
The elements of the dynamical matrix have been deduced by assuming,
on one hand, central "spring" interactions extending up to the sixth
neighbours and, on the other hand, screened Coulomb interactions
between all ions. The relations between the parameters introduced
in the model and the five elastic constants have been obtained by
means of the method of long waves. Calculations of the phonon
dispersion curves along the symmetry axes for 3e, Mg and Zn are
in progress.
An experimental investigation of the lattice dynamics of Zn has been
performed; scattering curves in the (001) plane have been deduced for
three different scattering angles. Our program is being extended