High-resolution X-ray photoelectron spectroscopy on giant magnetoresistive CoAg granular films sandwiched between Pt layers

The chemical state of Co, Ag and Pt in giant magnetoresistive CoAg granular films sandwiched between Pt layers is studied using high‐resolution x‐ray photoelectron spectroscopy. Measurements were carried out as a function of depth for samples deposited at different temperatures and containing different amounts of Co. In all samples Ag is found to segregate at the surface to form an AgPt alloy. The depth profiles are consistent with the deposited Co concentration modified by preferential sputtering. No variation of the chemical state for Co or Ag in the CoAg layer is found for different deposition conditions. However, small amounts of Pt do affect the Co 3d electrons. © 1998 John Wiley & Sons, Ltd.