Temperature and pressure dependence of the Yb valence state in YbMn∼0.17Si ∼1.89

Bodry Tegomo Chiogo (1) , Nicolas P. Martin (1) , Léopold V.B. Diop (1) , Bernard Malaman (1) , Daniel Malterre (1) , François Baudelet (2) , Lucie Nataf (2) , Thomas Mazet (1)

1 IJL - Institut Jean Lamour
2 SSOLEIL - Synchrotron SOLEIL

Single crystals of the non-stoichiometric YbMn∼0.17Si ∼1.89 intermetallic compound were investigated by room-temperature x-ray diffraction as well as by temperature and pressure-dependent x-ray absorption experiments at the Yb L 3 edge. The crystal structure can be described in the orthorhombic space group Cmcm or in the non-centrosymmetric P2 1 monoclinic space group. In both cases, the cell comprises two Yb sites of identical multiplicity with close coordination numbers and interatomic distances. The average Yb valence is found independent of temperature ν av ∼ 2.42. Such a low Yb valence is hardly compatible with the occurrence of local magnetism on Yb inferred from a previous study. The pressure dependence of the Yb valence at 10 K does not reveal any first-order transition. The average Yb valence increases continuously under pressure but remains far from trivalency (ν av ∼2.63) even under the highest external pressure used of 37 GPa.

Domaines: Matière Condensée [cond-mat]

Bodry Tegomo Chiogo, Nicolas P. Martin, Léopold V.B. Diop, Bernard Malaman, Daniel Malterre, et al.. Temperature and pressure dependence of the Yb valence state in YbMn∼0.17Si ∼1.89. Journal of Applied Physics, 2022, 132 (20), pp.205902. ⟨10.1063/5.0125875⟩. ⟨hal-03891295⟩