Spinmotive forces and torque transfer in spin valves

That the magnetization of the free layer of a spin valve is being "measured" is reflected in the angular dependence of the torque transfer term, which then differs from that given by Sloncewski. The usual form of the Gilbert relaxation term is not consistent with the second law of thermodynamics. When the usual derivative is replaced by a "particle derivative", relaxation is consistent with this law. It is implied that static solutions in which relaxation balances the torque transfer term are possible. Discussed is the concept of a spin-motive-force arising from the non-conservative part of the Stem-Gerlach force. This gives a real meaning to the term "spin-battery" and a spin inductance.