  The Mott relation between the electrical and thermoelectric transport
coefficients normally holds for phenomena involving scattering. However, the
anomalous Hall effect (AHE) in ferromagnets may arise from intrinsic spin-orbit
interaction. In this work, we have simultaneously measured AHE and the
anomalous Nernst effect (ANE) in Ga1-xMnxAs ferromagnetic semiconductor films,
and observed an exceptionally large ANE at zero magnetic field. We further show
that AHE and ANE share a common origin and demonstrate the validity of the Mott
relation for the anomalous transport phenomena.
