TY - JOUR
T1 - Low-temperature specific heat of Ni-Mn-Ga ferromagnetic shape memory alloys
AU - Chernenko, V. A.
AU - Fujita, A.
AU - Besseghini, S.
AU - Pérez-Landazabal, J. I.
N1 - Funding Information:
The authors are grateful to Fondazione Cariplo (Project 2004.1819-A10.9251) and DGI (Ministerio de Ciencia y Tecnologia, Project MAT2006-12838) for financial support.
PY - 2008/7
Y1 - 2008/7
N2 - Results of the low-temperature specific heat measurements (2-80 K) for one austenitic and three martensitic Ni-Mn-Ga ferromagnetic alloys are presented. The alloy compositions are chosen to comprise a wide span of valence electron concentrations e/a=7.3-7.78. Debye temperature (261-345 K) is found to be an increasing function of e/a while the experimental values of the Sommerfeld coefficient (2.9-3.4 mJ/mol K2) appear to be increasing in the martensitic region only. Observation of those trends rekindles the discussion about the role of vibrational and electronic contributions to the lattice instability and transformation mechanism of studied alloys.
AB - Results of the low-temperature specific heat measurements (2-80 K) for one austenitic and three martensitic Ni-Mn-Ga ferromagnetic alloys are presented. The alloy compositions are chosen to comprise a wide span of valence electron concentrations e/a=7.3-7.78. Debye temperature (261-345 K) is found to be an increasing function of e/a while the experimental values of the Sommerfeld coefficient (2.9-3.4 mJ/mol K2) appear to be increasing in the martensitic region only. Observation of those trends rekindles the discussion about the role of vibrational and electronic contributions to the lattice instability and transformation mechanism of studied alloys.
KW - Debye temperature
KW - Low-temperature specific heat
KW - Ni-Mn-Ga ferromagnetic shape memory alloy
KW - Sommerfeld coefficient
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U2 - 10.1016/j.jmmm.2008.02.139
DO - 10.1016/j.jmmm.2008.02.139
M3 - Article
AN - SCOPUS:42749087009
SN - 0304-8853
VL - 320
SP - e156-e159
JO - Journal of Magnetism and Magnetic Materials
JF - Journal of Magnetism and Magnetic Materials
IS - 14
ER -