Magnetic and thermal properties of IrMn/FeTaN films

Abstract

The antiferromagnetic–ferromagnetic exchange coupling between IrMn and FeTaN films has been investigated to study the effects of the exchange field on the high frequency response and the thermal stability of the anisotropy field of FeTaN. Ferromagnetic resonance, vibrating sample magnetometer, and torque measurements were used to determine the values of the unidirectional exchange bias field H p , the uniaxial anisotropy field H k and the interfacial energy J. Permeameter measurements to 3 GHz were used to study the effect of the exchange field on the low-frequency permeability and the high-frequency cutoff. Measurements on varying thicknesses of IrMn and FeTaN films gave H p values from 4 to 115 Oe, H k values from 10 to 20 Oe, H c values from 10 to 20 Oe, and an interfacial energy J=0.075 ergs/cm 2 . The exchange coupling was found to have significant effects on the permeability and the thermal stability of the anisotropy.