Electronic structures of CeNiSn, CePdSn, and CePtSn

Self-consistent first-principles band-structure calculations were performed on the isostructural heavy-fermion materials CeNiSn, CePdSn, and CePtSn. CeNiSn behaves as a heavy-fermion compound down to 7K where a small, anisotropic energy gap develops. In contrast CePdSn and CePtSn have magnetic, metallic ground states, both with T sub N =7.5K. The calculations reveal band structures in good agreement with experimental observations. An insulating band structure was found for CeNiSn which displays no tendency to form a magnetic ground state. This was interpreted to mean that the energy gap may be due to hybridization. For CePdSn and CePtSn, it was found that metallic ground states and spin-polarized calculations reveal the existence of a stable magnetic state for CePdSn with a moment of 0.86 mu sub B per cerium atom, while for CePtSn a magnetic state is only obtained when the lattice is expanded.