M. Sakurai et al., EXTENDED X-RAY-ABSORPTION FINE-STRUCTURE STUDY ON LOCAL-STRUCTURE AROUND FE ATOMS IN FE AG GRANULAR-MATERIALS/, JPN J A P 1, 33(7A), 1994, pp. 4090-4093
The short-range structure of Fe/Ag granular materials has been studied
by means of extended X-ray absorption fine structure (EXAFS). The loc
al structure around Fe atoms is a distorted bcc structure for the as-d
eposited state of Fe/Ag granular films produced by the ionized cluster
beam (ICB) deposition technique. Fe atoms are rather randomly distrib
uted in the Fe/Ag alloy films produced by cosputtering. With increasin
g annealing temperature and time, the local structure around Fe atoms
becomes a strain-free bcc structure in the ICB-deposited films, while
Fe clusters are formed in the sputter-deposited films. The formation o
f small Fe clusters and rough interfaces between the Fe cluster and th
e Ag matrix is responsible for giant magnetoresistance (GMR) in Fe/Ag
granular materials.