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Thermal properties of U 3 Al 2 Si 3 single crystal
Author(s) -
Mihalik Marián,
Flachbart Karol,
Gabáni Slavomír,
Maťaš Slavomír,
Mihalik Matúš,
Rogl Peter,
Troć Robert
Publication year - 2006
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200562433
Subject(s) - heat capacity , debye model , condensed matter physics , magnon , phonon , crystal (programming language) , superconductivity , band gap , physics , materials science , thermodynamics , ferromagnetism , computer science , programming language
Abstract Heat capacity data of U 3 Al 2 Si 3 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 K 2 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 K 2 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)