Role of spin in the composition-dependent electron-phonon coupling in Co-Fe alloys

We study from first principles the electron-phonon coupling strength in Co-Fe alloys across the full range of compositions. We decompose the Eliashberg spectral function and subsequently the electron-phonon coupling strength into majority-spin and minority-spin parts. The electron-phonon coupling strength changes significantly with composition. We identify spin-dependent quantities that drive the changes in electron phonon coupling strength. Finally, we show that these results are in qualitative agreement with experimental measurements.