Effect of electron-phonon scattering on the anomalous Hall conductivity of Fe3Sn: A kagome ferromagnetic metal

We report on magnetic and magnetotransport studies of the kagome ferromagnetic metal Fe3Sn. Our studies reveal a large anomalous Hall conductivity sigma(zx) in this system, mainly contributed by temperature-independent intrinsic Hall conductivity (sigma(int)(zx) = 485 +/- 60 S cm(-1)) and temperature-dependent extrinsic Hall conductivity sigma(ext)(zx) due to skew scattering. Although the sigma(ext)(zx) value is large and almost equivalent to the intrinsic Hall conductivity at low temperatures, it drastically decreases with increasing temperature, following the relation sigma(ext)(zx) = sigma(ext)(zx0)/(aT+1)(2), under the influence of electron-phonon scattering. The presence of electron-phonon scattering in this system is also confirmed by the linear dependence of the longitudinal electrical resistivity at higher temperatures [rho(T) proportional to T]. We further find that Fe3Sn is a soft ferromagnet with an easy axis of magnetization lying in the ab plane of the crystal with a magnetocrystalline anisotropy energy density as large as 1.02 x 10(6) J m(-3).