The low temperature heat capacity Cp of Fe1−xGax alloys with large magnetostriction has been investigated. The data were analyzed in the standard way using electron (γT) and phonon (βT3) contributions. The Debye temperature ΘD decreases approximately linearly with increasing Ga concentration, consistent with previous resonant ultrasound measurements and measured phonon dispersion curves. Calculations of ΘD from lattice dynamical models and from measured elastic constants C11,C12, and C44 are in agreement with the measured data. The linear coefficient of electronic specific heat γ remains relatively constant as the Ga concentration increases, despite the fact that the magnetoelastic coupling increases. Band structure calculations show that this is due to the compensation of majority and minority spin states at the Fermi level.
Available at: http://works.bepress.com/thomas_lograsso/61/