  The Righi-Leduc effect refers to the thermal analogue of the Hall effect, for
which the electric current is replaced by the heat current and the electric
field by the temperature gradient. In both cases, the magnetic field generates
a transverse force that deviates the carriers (electron, phonon, magnon) in the
direction perpendicular to the current. In a ferromagnet, the magnetization
plays the role of the magnetic field, and the corresponding effect is called
anomalous Hall effect. Furthermore, a second transverse contribution due to the
anisotropy, the planar Hall effect, is superimposed to the anomalous Hall
effect. We report experimental evidence of the thermal counterpart of the Hall
effects in ferromagnets, namely the magnon Hall effect (or equivalently the
anomalous Righi-Leduc effect) and the planar Righi-Leduc effect, measured on
ferromagnets that are either electrical conductor (NiFe) or insulator (YIG).
The study shows the universal character of these new thermokinetic effects,
related to the intrinsic chirality of the anisotropic ferromagnetic degrees of
freedom.
