Open AccessLayered structure analysis of GMR multilayers by X‐ray reflectometry using the anomalous dispersion effect
Author(s) -
Hirano Tatsumi,
Usami Katsuhisa,
Ueda Kazuhiro,
Hoshiya Hiroyuki
Publication year - 1998
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s0909049597017299
Subject(s) - reflectometry , materials science , dispersion (optics) , giant magnetoresistance , absorption (acoustics) , absorption edge , enhanced data rates for gsm evolution , substrate (aquarium) , analytical chemistry (journal) , condensed matter physics , copper , magnetoresistance , optics , chemistry , optoelectronics , metallurgy , composite material , physics , band gap , time domain , telecommunications , oceanography , chromatography , quantum mechanics , computer science , magnetic field , computer vision , geology
As a basic layered structure for giant magnetoresistive (GMR) heads, NiFe/Cu/NiFe/Ta/Si substrate was measured by X‐ray reflectometry at Cu K α, Cu K β and Cu K ‐absorption‐edge energies. The accuracy of both the Cu thickness and the interface width between the upper NiFe and the Cu layers was found to improve in the order Cu K α < Cu K β < Cu K ‐edge. The final thickness and interface width values obtained from Cu K β reflectivity are in good agreement with those from the Cu K ‐edge. The anomalous‐dispersion effect is useful in the more accurate analysis of the layered structure of transition metal multilayers because it causes a large difference in the refractive indices of specific elements near the absorption edge. The K β X‐rays, which can be produced from conventional X‐ray sources, are also available for the accurate analysis of reflectivity measurements.