Magnetostriction and stress of Ta/(Cu/Co90Fe10)×N/Ta multilayer films

Abstract

The magnetostriction and stress of multilayer Ta 50 Å/(Cu/Co90Fe10)×N/Ta 50 Å films were investigated. As the number of Cu 15 Å/CoFe 15 Å bilayers was increased, the saturation magnetostriction decreased from −2×10−6 at 2 bilayers to −7×10−6 at 20 bilayers. A change of CoFe thickness from 5 to 25 Å caused a decrease in the magnitude of the magnetostriction of about 1×10−6. Stress measurements showed a decrease in the magnitude of compressive stress from 1 100 MPa to nearly zero as the number of Cu 15 Å/CoFe 15 Å bilayers increased from 2 to 20. The maximum magnetostrictive anisotropy that could be developed due to nonzero magnetostriction and stress is calculated to be 45.0 Oe when the number of Cu 15 Å/CoFe 15 Å bilayers is 10.