A vertically graded anisotropy profile has been proposed as an optimized balance of low coercivity and thermal stability for multilayers used in magnetic media. Deposition pressure is known to have a profound effect on the magnetic reversal properties of Co/Pd multilayers, making it an attractive control parameter for achieving an anisotropy gradient. We have used polarized neutron reflectometry to study the depth-dependent reversal behavior of "pressure-graded" Co/Pd, and observed pronounced gradients in the saturation magnetization and in the rate at which magnetization changes with field (the effective anisotropy). While the anisotropy gradient likely arises from a combination of factors intrinsic to deposition pressure, micromagnetic simulations indicate that the observed saturation magnetization gradient alone has a major effect on the resulting coercivity.
@article{arxiv.1403.2126,
title = {Effective anisotropy gradient in pressure graded [Co/Pd] multilayers},
author = {B. J. Kirby and P. K. Greene and B. B. Maranville and J. E. Davies and Kai Liu},
journal= {arXiv preprint arXiv:1403.2126},
year = {2015}
}