Thermal properties of U3Al2Si3 single crystal

• Published in: Physica Status Solidi (b) Vol. 243; no. 1; pp. 304 - 308
• Main Authors: Mihalik, Marián, Flachbart, Karol, Gabáni, Slavomír, Maťaš, Slavomír, Mihalik, Matúš, Rogl, Peter, Troć, Robert
• Format: Journal Article
• Language: English
• Published: Berlin WILEY-VCH Verlag 01-01-2006; WILEY‐VCH Verlag
• Subjects: 65.40.Ba; 65.40.Gr; 75.40.Cx; 75.50.Gg
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/pssb.200562433

Heat capacity data of U3Al2Si3 single crystal exhibit a maximum at 38 K connected with a transition to a magnetically ordered state. For a full description of the electron part we used γ 0 = 145 mJ/mol K2 and for the phonon part of the specific heat we used the harmonic approximation of the phonon spectrum including both the Debye model with T D = 296 K and the Einstein model with T E = 136, 249 and 438 K. The heat capacity data below the magnetic transition down to 2 K fit very well within the model introducing the energy gap Δ = 39 K in the dispersion relation of magnons. An upturn of the C /T (T ) curve, found below T = 2 K, can not be fully attributed to the nuclear Schottky contribution. The electronic heat capacity coefficient (γ ≈ 230 mJ/mol K2 is enhanced and varies between 0.15 K and 12 K as the square root of T . (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)