Controlling the shapes of coated silicon substrates via magnetic fields, a progress report

Melville P. Ulmer*, Rocco Coppejans, David B. Buchholz, Jian Cao, Xiaoli Wang, Alejandro M. Mercado, Jun Qian, Lahsen Assoufid, Allison E. O'Donnell, Kyle S. Condron, Benjamin E. Harpt

*Corresponding author for this work

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

3 Scopus citations


We describe our progress in developing a method for correcting residual figure errors in X-ray mirrors. The technology has applications to both synchrotron radiation beamlines and X-ray astronomy. Our concept is to develop mirrors that are on the order of a millimeter thick. A magnetic smart material (MSM) is deposited onto the mirror substrate (silicon) and coated with a magnetically hard material. The shape of the mirror can be controlled by applying an external magnetic field to the mirror. This causes the MSM to expand or contract, thereby applying a magnetostrictive stress to the mirror and changing its shape. The shape change is maintained after the field has been removed by the magnetic hard material, which retains part of the field and prevents the MSM from relaxing. Here we present the results of shaping 200 μm thick silicon (100) 14 × 2 mm cantilevers and 50 × 50 × 0.1 mm substrates. We demonstrate that not only can a sizable deflection be created, but it can also be retained for â1/4 60 hours.

Original languageEnglish (US)
Title of host publicationOptics for EUV, X-Ray, and Gamma-Ray Astronomy VIII
EditorsStephen L. O'Dell, Giovanni Pareschi
ISBN (Electronic)9781510612556
StatePublished - 2017
EventOptics for EUV, X-Ray, and Gamma-Ray Astronomy VIII 2017 - San Diego, United States
Duration: Aug 8 2017Aug 10 2017

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


OtherOptics for EUV, X-Ray, and Gamma-Ray Astronomy VIII 2017
Country/TerritoryUnited States
CitySan Diego


  • X-ray optics
  • grazing incidence optics
  • magnetic smart materials

ASJC Scopus subject areas

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


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