  Here we report on measurements of the spin-Seebeck effect of GaMnAs over an
extended temperature range alongside the thermal conductivity, specific heat,
magnetization, and thermoelectric power. The amplitude of the spin-Seebeck
effect in GaMnAs scales with the thermal conductivity of the GaAs substrate and
the phonon-drag contribution to the thermoelectric power of the GaMnAs,
demonstrating that phonons drive the spin redistribution. A phenomenological
model involving phonon-magnon drag explains the spatial and temperature
dependence of the measured spin distribution.
