Electronic structure and magnetic properties of the magnetically ordered intermediate valent Ce5RuGe2

We report here a comprehensive investigations of the band structure, magnetic properties, electrical transport, and specific-heat for ternary compound Ce5RuGe2 that crystallize in orthorhombic Y2HfS5-type structure. The results show a complex magnetic structure with the field-induced metamagnetic transitions in coexistence with spin-glass-like phase, displayed in the magnetic H−T phase diagram. Simultaneously, a combined experimental and theoretical study based on x-ray photoelectron spectroscopy (XPS) data together with ab initio band structure calculations indicate a mixed valence of Ce due to strong hybridization between Ce 4f states and conduction band. The obtained magnetic ground state of Ce5RuGe2, resulting from localized f-electron states and accompanying strong hybridization effect leading to valence instability of cerium ions are rarely observed for Ce-based intermetallic compounds.