Spin Transport Through Antiferromagnetic/Paramagnetic IrMn Layer Using Second Harmonic Method.

We investigate the spin transmission through an antiferromagnetic or paramagnetic IrMn layer by using second harmonic methods. The film //Ta5/IrMn0-3/Cu1/Py3 was deposited by sputtering and a Hall bar pattern was then fabricated by photolithoghy. By change the thickness of IrMn layer and the measurement temperature, we found that antiferromagnetic and paramagnetic phase do not have significant influence on spin transport. The dampinglike torque and fieldlike torque decease when temperature goes down. We also use FMR to examine the spin absorption rate in //Cu3/Py10/Cu3/IrMn0-3/Cu3 sample. The thickness of IrMn layer does have influence on the spin absorption rate but without significant difference when the temperature is above and below Neel temperature.