  A thermal gradient as the driving force for spin currents plays a key role in
spin caloritronics. In this field the spin Seebeck effect (SSE) is of major
interest and was investigated in terms of in-plane thermal gradients inducing
perpendicular spin currents (transverse SSE) and out-of-plane thermal gradients
generating parallel spin currents (longitudinal SSE). Up to now all spincaloric
experiments employ a spatially fixed thermal gradient. Thus anisotropic
measurements with respect to well defined crystallographic directions were not
possible. Here we introduce a new experiment that allows not only the in-plane
rotation of the external magnetic field, but also the rotation of an in-plane
thermal gradient controlled by optical temperature detection. As a consequence,
the anisotropic magnetothermopower and the planar Nernst effect in a permalloy
thin film can be measured simultaneously and reveal a phase shift, that allows
the quantitative separation of the thermopower, the anisotropic
magnetothermopower and the planar Nernst effect.
