Strong uniaxial crystal field and ising like exchange interaction of ferromagnet CeAgSb2

Abstract Neutron scattering experiments have been performed to reveal the magnetic excitation in ferromagnet CeAgSb2. Crystalline electric field excitations were observed at 5.2 and 12.5 meV in the paramagnetic state. Our analysis concluded that | ± 1 2 〉 is the ground state. The observed ferromagnetic moment is in good agreement with the ground-state saturation moment, g J μ B J z ∼0.43 μ B . The spontaneous moment along the c-axis decreases with increasing the field perpendicular to the c-axis, and disappear at the critical field Hc, where the magnetization curve shows the kink behavior.