Inelastic neutron scattering study of Pr2Co12Fe5.

Abstract

Inelastic neutron scattering measurements have been performed on the intermetallic compounds Pr2Co12Fe5 (and Y2Co12Fe5) on the IN4 time-of-flight spectrometer at the Institut Laue-Langevin, Grenoble. The data on the yttrium-based compound have been used to estimate the phonon scattering. A broad peak is detected at 18 meV, whose deduced Q dependence (when only the magnetic contribution is considered) is consistent with the form factor of Pr3+ ions; in the high-Q region, the same peak displays a clear phononic character. The experimental results are analysed by a molecular field model including exchange and crystal-field contributions, and the derived value for the exchange parameter is consistent with the trend inferred by studying Pr2Co17 and Pr2Fe17. A possible mechanism for the generation of the large volume magnetostriction, to be checked by further experiments, is suggested. © 2008, Institute of Physics