Anisotropy constant of antiferromagnetic Pt₅₀Mn₅₀

Abstract

We have measured the anisotropy constant of polycrystalline PtMn thin films deposited on different seed layer materials: Pt, Ru and Nb. Values as high as (2.5 ± 0.5) · 107 erg/cm3 were achieved for samples deposited on Pt. The films can be crystallised into the antiferromagnetic, face-centred-tetragonal phase on Ru and Pt seed layers at annealing temperatures compatible with back-end-of-line conditions of up to 400 ◦C for one to three hours. Additionally these antiferromagnetic layers, 8 nm thick, are highly thermally stable with median blocking temperatures above 200 ◦C. The effect of diffusion on the stoichiometry of the PtMn layers is discussed with regards to the different seed layer materials.