Low temperature heat capacity of Fe1-xGax alloys with large magnetostriction

TitleLow temperature heat capacity of Fe1-xGax alloys with large magnetostriction
Publication TypeJournal Article
Year of Publication2008
AuthorsHill JM, McQueeney RJ, Wu R, Dennis K, McCallum RW, Huang M, Lograsso TA
Journal TitlePhysical Review B
Date PublishedJan
Type of ArticleArticle
ISBN Number1098-0121
Accession NumberISI:000252862200072
Keywordsfe-ga, iron, magnetoelasticity, metals, NI-FE

The low temperature heat capacity C-p of Fe1-xGax alloys with large magnetostriction has been investigated. The data were analyzed in the standard way using electron (gamma T) and phonon (beta T-3) contributions. The Debye temperature Theta(D) decreases approximately linearly with increasing Ga concentration, consistent with previous resonant ultrasound measurements and measured phonon dispersion curves. Calculations of Theta(D) from lattice dynamical models and from measured elastic constants C-11, C-12, and C-44 are in agreement with the measured data. The linear coefficient of electronic specific heat gamma 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.

Alternate JournalPhys. Rev. B