Neutron Scattering Investigation of the Ferromagnetic Heavy Fermion System CeSi_1.76Cu_0.24

Abstract

Neutron scattering measurements on the heavy fermion system CeSi_1.76Cu_0.24 confirm a phase transition to ferromagnetic order below T_c=8 K. The ordered moment μ=0.62±0.05 μ_B is about four times smaller than the effective moment above T_c and agrees well with the saturation moment determined by dc-magnetization measurements. The moments lie in the basal plane of the tetragonal unit cell. The very weak critical magnetic scattering suggests a new type of local moment formation below T_c.