  In this work we report observation of in-plane current induced out-of-plane
magnetic field driven torque in spin valve structure. Since ferromagnet has
high spin orbit coupling it is expected to be the source of spin-orbit-torque
as it possesses anomalous-Hall-effect (AHE: equivalent to spin Hall effect in
heavy metal). So we have carried out spin-torque ferromagnetic resonance
(ST-FMR) experiment in a spin valve (consists of a fixed magnet and a free
magnet which are separated by Cu spacer), passing in-plane radio frequency
current and measuring DC voltage. Our experimental results eventually indicate
that spin torque exerted on the free magnet is not caused due to the spin
current injection by the fixed magnet owing to its AHE, but it is originated
from in-plane current driven out-of plane effective magnetic field. This is new
class of spin torque which is completely different from Slonczewski-spin
transfer torque and Rashba like field like torque. The effective out-of plane
magnetic field depends on the direction of current (in-plane) and magnetization
(in-plane) of the pinned layer. One possible mechanism behind this
unconventional torque could be intefacial spin-scattering which is also origin
of current in-plane GMR effect. Most importantly this effective out-of plane
torque can be useful to switch out-of plane magnetic bits in spintronic memory
application.
