Thermopower of Ce1–xLaxCu4Al in applied magnetic fields

Abstract Here we report the continued investigations of thermopower S ( T ) for Ce 1– x La x Cu 4 Al intermetallic alloys, particularly focusing on the influence of the applied magnetic fields. In comparison to CeCu 4 Al, the substitution of Ce by La reduces the S ( T ) values. S ( T ) of Ce 1– x La x Cu 4 Al compounds exhibit positive values and large maximum at T max  ≈ 30 K. However, the positive sign of S ( T ) for Ce 1– x La x Cu 4 Al is consistent to that generally observed in Ce-based systems, which is positive due to the location of a narrow Kondo resonance peak slightly above the Fermi energy level ( E F ). The large peak may be due to the Kondo effect in the presence of a crystal-field splitting (CEF) of the Ce 4f-electron. The peak position and absolute value above T max of S ( T ) is unaffected by an applied magnetic field. At low temperatures the S ( T ) value depends strongly on the magnetic field. The S / T ( T ) shows a strong temperature dependence at low temperature which is consistent with the temperature dependence of heat capacity and electrical resistivity.