Dependence of the Exchange Bias and Coercivity of [Pd/Ferromagnet]N/FeMn Multilayers on the Stack NumberN

Abstract

The dependencies of the stack number N on perpendicular exchange-biasing (Hex) and coercivity Hc ) in [Pd/Co] N and [Pd/Co (or CoFe)] N /FeMn multilayers were investigated. With the help of the careful designs of layer structures, a series of samples whose surface anisotropies have the linear function N was prepared with constant bulk anisotropies. From the experimental data obtained, it was found that Hex does not depend on the surface anisotropy, while Hc shows a strong dependence. Therefore, it is possible to tailor wide ranges of Hc (300–600 Oe) without varying Hex ( sim!hbox200 Oe) through the single control parameter stack number N .