Magnetostriction measurements of powder-sintered samples using pulsed
magnetic fields up to 15 T and between 25 and 300 K have been performe
d. The strains were measured parallel, perpendicular and at 450 from t
he c-axis, with the field parallel and perpendicular to these directio
ns. To explain the thermal dependence of the irreducible strains, the
standard magnetostriction model has been extended to take into account
the excited spin-orbit coupling multiplets of the Sm3+ ion.