Enhanced Sommerfeld coefficient near the quantum critical point in YbMn6Ge6−xSnx. (January 2022)

• Record Type: Journal Article
• Authors: Haraux, P.; Eichenberger, L.; Diop, L.V.B.; Mazet, T.
• Is Part Of: Solid state communications. Volume 341(2022)
• Publication Date: 2022-01
• Subjects: A. Yb-based intermetallics -- D. Heavy fermion quantum criticality -- E. Specific heat; Solid state chemistry -- Periodicals; Solid state physics -- Periodicals; Chimie de l'état solide -- Périodiques; Physique de l'état solide -- Périodiques; 530.41
• DOI: 10.1016/j.ssc.2021.114551
• Languages: English
• ISSNs: 0038-1098

Abstract

Abstract: We investigate the YbMn6 Ge 6 − x Sn x alloys (4.00 ≤ x ≤ 5.55) by means of specific heat measurements in the temperature range 1.9 to 200 K. For x near ∼ 4.0, the Sommerfeld coefficient γ is close to that of a Lu-based counterpart ( γ ∼ 40 mJ.mole −1 .K −2 ). The γ coefficient increases upon Sn for Ge substitution, enters the heavy fermion regime and peaks ( γ ∼ 210 mJ.mole −1 .K −2 ) in the vicinity of the Yb magnetic instability ( x c ∼ 5.23), before diminishing upon further Sn content increase. The enhanced γ values near x c agree with the close proximity of a quantum critical point previously inferred from electronic spectroscopy experiments. Highlights: First C p measurements on YbMn6 Ge6- x Sn x . Heavy fermion behavior for x ≳ 5. Quantum critical point near x c ∼ 5.23.