Magnetic, electronic and thermodynamic properties of the heavy fermion compound CeNiAl4

We have carried out the magnetic susceptibility, electrical resistivity, specific heat, thermoelectric power and X-ray photoemission spectroscopy (XPS) measurements for CeNiAl4. The magnetic susceptibilities have revealed a Curie–Weiss behavior above 30 K with a large negative paramagnetic Curie temperature θP = −66 K and an effective moment of 2.45μB. The f-occupancy and the coupling between the f level and the conduction states are derived from XPS to be about 0.83 and ∼40–64 meV, respectively. The valence state of the Ce ion is close to 3+. Extrapolation of the lowest temperatures range of C/T(T2) yields the electronic specific heat coefficient γ = 0.5 J mol−1 K−2. In combination with the thermoelectric power and resistivity data, a heavy fermion state is confirmed in CeNiAl4.