Intermultiplet transitions in filled skutterudite SmFe4P12

Abstract

The intermultiplet transitions in filled skutterudite SmFe4P12 are studied by magnetization and time-of-flight inelastic neutron scattering experiments. In neutron scattering experiments by using high energy neutrons for reducing huge neutron absorption of natural Sm, a small inelastic peak has been observed around ~80 meV at low temperature. The scattering vector dependence of intensity of this peak agrees with the theoretical inelastic structure factor for the intermultiplet transition from the ground J = 5/2 multiplet to the excited J = 7/2 multiplet in Sm3+ ion. Interestingly, the energy splitting is much smaller than the free Sm3+ ion value. This is also comparable with that estimated by the inverse magnetic susceptibility. This large reduction of the energy splitting might be due to the strong c-f mixing in SmFe4P12.