Title: Evidence for persistent spin fluctuations in uranium sesquicarbide
Authors: ELOIRDI RachelFUCHS AndreasGRIVEAU Jean-ChristopheCOLINEAU EricSHIK ALEXANDERMANARA DarioCACIUFFO Roberto
Citation: PHYSICAL REVIEW B vol. 87 no. 21 p. 214414-1 - 214414-9
Publisher: AMER PHYSICAL SOC
Publication Year: 2013
JRC N°: JRC79196
ISSN: 1098-0121
URI: http://prb.aps.org/abstract/PRB/v87/i21/e214414
http://publications.jrc.ec.europa.eu/repository/handle/JRC79196
DOI: 10.1103/PhysRevB.87.214414
Type: Articles in periodicals and books
Abstract: The low-temperature magnetic susceptibility, heat capacity and electrical resistivity of uranium sesquicarbide have been estimated down to 2 K by combining measurements carried out on samples of U2C3, containing UC as minority phase, and on pure UC specimens. The presence of spin fluctuations with characteristic temperature TSF = 7 K is revealed by a nonanalytic contribution to the specific heat behaving (well below TSF ) as T3ln(T=TSF), and confirmed by a T2 increase of the electrical resistivity and a 1 κT2 decrease of the low-temperature magnetic susceptibility. The analysis of the specific heat data above TSF provides a Debye temperature ΘD ≈ 256 K and a moderately high value of the Sommerfeld coefficient, γ 42.4 mJmol -1 U K -2. The zero-temperature many-body enhancement of the electron mass is found to be m *m ≈ 2.7. Our data rule out the occurrence of magnetic ordering in U2C3. First principles electronic structure calculations support the absence of a magnetically ordered ground state but suggest that dynamical spin fluctuations are responsible for the electron mass enhancement.
JRC Directorate:Nuclear Safety and Security

Files in This Item:
There are no files associated with this item.


Items in repository are protected by copyright, with all rights reserved, unless otherwise indicated.