LAUSR

We have investigated the anomalous Nernst effect (ANE) in $\mathrm{F}{\mathrm{e}}_{1\ensuremath{-}x}\mathrm{G}{\mathrm{a}}_{x}$ alloy films with different Ga atomic compositions ($x=0\ensuremath{-}0.44$) deposited on MgO(001) single-crystalline substrates. We found that the magnitude of the ANE increases with increasing $x$ up to $x=0.32$ even though the saturation magnetization decreases with increasing $x$, suggesting a dominant contribution of the intrinsic mechanism on the observed ANE. The magnitude of the ANE reaches $2.4\phantom{\rule{0.16em}{0ex}}\ensuremath{\mu}\mathrm{V}/\mathrm{K}$ in bcc ${\mathrm{Fe}}_{0.68}{\mathrm{Ga}}_{0.32}$ film, which is two orders of magnitude greater than that of pure Fe film. The magnetotransport measurements and the first-principles calculations revealed that the large ANE in bcc $\mathrm{F}{\mathrm{e}}_{1\ensuremath{-}x}\mathrm{G}{\mathrm{a}}_{x}$ is caused by the large transverse Peltier coefficient. The drastic enhancement of the transverse Peltier coefficient with increasing $x$ can be attributed to small Fermi level tuning through the electron doping effect. Thus, we anticipate that our finding will provide a crucial piece of information to enhance the thermopower through the ANE.