title: Measurement of femtometre-scale atomic displacements by X-ray absorption spectroscopy.
abstract: The frequencies of extended X-ray absorption fine-structure (EXAFS) measurements, which are oscillations occurring on the high-energy side of an X-ray absorption edge, can be used to identify interatomic distances in materials. We have used a dispersive X-ray spectrometer, which has no moving components, to make rapid measurements with minimal energy drift of the difference in EXAFS from the Fe K edge in an iron-cobalt thin film undergoing periodic strain through magnetostriction. We show that magnetostriction can be detected by differential X-ray absorption. The magnitude of the recorded signal relative to the noise shows a sensitivity to mean differential atomic motion of one femtometre: a factor of 100 times more sensitive than that normally available.
authors.affiliation: Department of Physics, University of Warwick, Coventry CV4 7AL, UK. r.pettifer@warwick.ac.uk
authors.forename: Robert F
authors.initials: RF
authors.lastname: Pettifer
authors.forename: Olivier
authors.initials: O
authors.lastname: Mathon
authors.forename: Sakura
authors.initials: S
authors.lastname: Pascarelli
authors.forename: Michael D
authors.initials: MD
authors.lastname: Cooke
authors.forename: Michael R J
authors.initials: MR
authors.lastname: Gibbs