Volume collapse transition in TmTe; Competition between strong correlation and f-d hybridization at high pressure

Jarrige, I.; Rueff, J.-P.*; Shieh, S.*; Wang, J.*; Matsumura, Takashi*; Ishii, Hirofumi*; Hiraoka, Nozomu*; Cai, Y.*

The pressure-induced mixed-valent state in TmTe is investigated up to 10.6 GPa using resonant inelastic X-ray scattering (RIXS) and the Anderson impurity model (AIM). The volume collapse transition (VCT) which takes place over the 24.3 GPa range is accompanied by a strong increase in the 4f-5d hybridization. The valence in the collapsed state is found to be 2.5, showing that the VCT is inconsistent with the commonly accepted picture of Tm to Tm conversion. At 6 GPa, a transition in both magnetic and electronic ground states occurs at constant valence and hybridization. This could be indicative of a non-trivial instability of the 4f ground state such as a non Fermi liquid behavior.