CeCoIn₅ and Ce₃PdIn₁₁ are interesting compounds exhibiting heavy fermion state and superconductivity below 2.3 K and 0.58 K, respectively. Moreover, two transitions to antiferromagnetic state take place in Ce₃PdIn₁₁ at temperatures of 1.68 K and 1.56 K.

Angle resolved photoemission spectroscopy (ARPES) was carried out using a Ce 4d-4f resonance photon energy (122 eV) at the temperature of 6 K. Fermi surface (FS) maps in different geometries obtained with on- and off-resonance radiation served to find the distribution of f-electrons. In particular, on-resonance symmetrized FS map for CeCoIn₅ agrees with the theoretical distribution of f-electrons in k-space obtained from tight-binding model for Ce-In planes [1]. Hybridization effects between Ce 4f electrons and valence band form heavy bands, which are visible. The estimated heavy electron masses for CeCoIn₅ amount to 30 – 130 free electron masses, depending on the location in reciprocal space. SPR-KKR package was employed to calculate Bloch spectral functions and simulate photoemission spectra within the one-step model calculations. This indicated that states related to Ce-In surface yield the most intensive spectra in the case of CeCoIn₅. Fermi surface of Ce₃PdIn₁₁ has similar features to the ARPES data for Ce₂PdIn₈, Ce₂RhIn₈, Ce₂IrIn₈ indicating the actual surface termination related to 218 systems. Ce₃PdIn₁₁ is a particularly interesting material due to two inequivalent crystallographic Ce sites. Their contribution to the band structure was identified by SPR-KKR calculations.

References

[1]. Kurleto R., et al., Phys. Rev. B 104, 125104 (2021).