  The anomalous Nernst effect (ANE), a thermoelectric phenomenon in magnetic
materials, has potential for novel energy harvesting applications because its
orthogonal relationship between the temperature gradient and the electric field
enables us to utilize the large area of non-flat heat sources. In this study,
the required thermopower of ANE for practical energy harvesting applications is
evaluated in simulations of electric power obtainable from ANE using a
low-temperature heat source. A strategy for finding magnetic materials having
large ANEs is proposed, which suggests that a large ANE originates from the
constructive relationship between large Seebeck, anomalous Hall, and transverse
Peltier effects. This strategy leads us to investigate the electric and
thermoelectric properties in Co2MnAl1-xSix. As a result, it is found that
Co2MnAl0.63Si0.37 has the largest ANE thermopower ever reported, 6.2 uV/K. A
first principles calculation of the anomalous Hall conductivity and transverse
Peltier coefficient in B2 and L21-ordered Co2MnAl0.63Si0.37 shows close
agreement with the experimental results, indicating that the observed large ANE
arises from the intrinsic Berry phase curvature of Co2MnAl1-xSix. This study
can be a guide for developing materials for new thermoelectric applications
using ANE.
