Specific heat and electronic structure of Heusler compounds Ni2TAl (T = Ti, Zr, Hf, V, Nb, Ta)

Low-temperature specific heat measurements (3.2 to 10.3 K) of Ni2TAl (T = T i, Zr, Hf, V, Nb, Ta) Heusler compounds are presented. Experimental data ar e well described by the electronic and Debye lattice specific heat contribu tions, plus one Einstein term. The electronic structure of the compounds is calculated using the LMTO-TB method. The experimental to theoretical ratio s (R) of the electronic specific heat coefficient (gamma) were determined f or the isoelectronic compounds corresponding to Ti and V. The electron-fono n coupling constants (lambda) were extracted from these R values. A simple estimate of the elastic constant ratio is also made. (C) 1999 Elsevier Scie nce B.V. All rights reserved.