rf-sputtered Fe/Ge multilayers for neutron-polarizing monochromators

Pierre Boher, Philippe Houdy, M. Monkenbusch, J. Penfold, J. Eastoe, David J. Smith

Research output: Chapter in Book/Report/Conference proceedingConference contribution

6 Scopus citations

Abstract

State of the art diode rf-sputtering is used to fabricated high quality polarizing monochromators for neutrons. Optimization of the deposition parameters is achieved using in- situ kinetic ellipsometry and a great number of ex-situ characterization techniques such as grazing x-ray reflection, x-ray diffusion, alternating field gradient magnetometry. Mossbauer spectrometry, and electron microscopy. A precise picture of the structural characteristics of the system is deduced and related to the neutron performance as measured by polarized neutron reflectometry. We show that the structural behavior is controlled by crystallization of the iron layers and by the occurrence of amorphous interdiffused layers at each interface. As a consequence, the polarizing efficiency of these mirrors depends directly on the amount of iron involved in the interdiffusion. Using optimized deposition conditions, the flipping ratio is found to be around 40 for Fe/Ge mirrors with a medium period value of 120 angstroms. Positive spin-state reflectivity at the first Bragg peak is close to 100% when 150 bilayers are included and a controlled graded layer thickness allows the angular acceptance to be enhanced up to 39%.

Original languageEnglish (US)
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
PublisherPubl by Int Soc for Optical Engineering
Pages176-189
Number of pages14
ISBN (Print)0819409111
StatePublished - Dec 1 1992
Externally publishedYes
EventNeutron Optical Devices and Applications - San Diego, CA, USA
Duration: Jul 22 1992Jul 24 1992

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume1738
ISSN (Print)0277-786X

Other

OtherNeutron Optical Devices and Applications
CitySan Diego, CA, USA
Period7/22/927/24/92

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

Fingerprint Dive into the research topics of 'rf-sputtered Fe/Ge multilayers for neutron-polarizing monochromators'. Together they form a unique fingerprint.

  • Cite this

    Boher, P., Houdy, P., Monkenbusch, M., Penfold, J., Eastoe, J., & Smith, D. J. (1992). rf-sputtered Fe/Ge multilayers for neutron-polarizing monochromators. In Proceedings of SPIE - The International Society for Optical Engineering (pp. 176-189). (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 1738). Publ by Int Soc for Optical Engineering.