Magnetism and electronic structure of the intermetallic compound Ce₅CuBi₃

Abstract

We have studied the electronic structure as well as magnetic, electronic transport and thermodynamic properties of the intermetallic compound Ce₅CuBi₃. It was found that Ce₅CuBi₃ undergoes three successive phase transitions at 25 K, 13.7 K and 3.5 K. We attribute the multiple magnetic phase transition to be associated with the two non-equivalent magnetic sublattices of the magnetic Ce ions. The investigated compound is characterized by an enhanced ratio C_p /T at 2 K, which may be interpreted as being due to the nearness of the 4f-level to the Fermi level and some contribution of magnon excitation. The core-level photoemission spectra indicate that Ce ions in Ce₅CuBi₃ are very close to trivalent which is consistent with the magnetic susceptibility data. The calculated band structures using the scalar-relativistic linear muffin-tin orbital method in the atomic sphere approximation and the all-electron full potential linear augmented plane wave plus local orbitals method have been performed for the non-magnetic ground state and as well as for collinear ferromagnetic and ferrimagnetic spin alignments. The largest stabilization energy is found in the case of a ferromagnetic structure. The calculated moments on the two sites of the Ce atoms are in agreement with the experimental value (0.93 μ _B /Ce). The calculations predict that the studied compound has a pseudogap in the DOS curve. Analysis of the partial DOS suggests some differences in hybridization strengths between the Ce-Bi and Ce-Cu orbitals.

Acknowledgments

VHT wishes to acknowledge financial support from the Ministry of Science and Higher Education in Poland with grant No N202 082 31/0449. Two of us (MG and A Ś) acknowledge the support of the Ministry of Science and Higher Education through grant No 1 P03B 052 28.