Wh. Flores et al., X-ray-absorption spectroscopy and x-ray diffraction in discontinuous CoxFe1-x/Ag multilayers, PHYS REV B, 61(5), 2000, pp. 3286-3296
This paper reports on the structural properties of CoxFe1-x/Ag discontinuou
s multilayers with x = 0, 0.3, 0.7, and 1. The evolution of the structural
properties has been investigated by x-ray diffraction and x-ray-absorption
spectroscopy (XAS). Thermal treatments for 10 min at temperatures ranging b
etween 200 and 800 degrees C, lead to breakup of the layers forming a heter
ogeneous alloy with magnetic clusters embedded in a metallic Ag matrix. The
as-deposited Co/Ag presents a high compressive stress, while a slight tens
ile stress is observed in every other composition. After annealing there is
a relaxation of the stress as well as a crystallo-graphic ordering of the
magnetic clusters. It is found from XAS measurements that, for the alloys w
ith x = 0.3 and 0.7, there is a better-ordered structure around Co than Fe
absorbing atoms. We conclude that Co atoms are within the core of the magne
tic clusters, while Fe atoms occupy preferentially the interfacial position
s near Ag. Co atoms in Co/Ag multilayers have a fee structure.