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Title: Soft x-ray optical constants of sputtered chromium thin films with improved accuracy in the L and M absorption edge regions

In this paper, we determine with improved accuracy the complex index of refraction n = 1 - δ + iβ of sputtered chromium thin films for photon energies ranging from 25 eV to 813 eV. These data include the first absolute measurements of the absorption fine structure near the Cr-L edge. First, we verified by combining Rutherford Backscattering Spectrometry and grazing-incidence x-ray reflectometry that the sputtered thin films were pure Cr with a density consistent with tabulated values. Then, we demonstrated that the Cr surface oxide layer remains stable when the samples are exposed to air for up to 4 years. The Cr absorption coefficient β was determined from the transmittance of freestanding Cr thin films with various thicknesses, measured at the ALS synchrotron radiation source. A model is proposed to correct the transmittance data from the spectral contamination of the source. Finally, we used the new β values, combined with theoretical and tabulated data from the literature, in order to calculate the δ values by the Kramers-Kronig relation. The improvement in the accuracy of β values is demonstrated by the f-sum rule. Finally, an additional validation of the new Cr optical constants (δ, β) is performed by comparing themore » simulated and experimental reflectance of a Cr/B 4C multilayer mirror near the Cr-L 2,3 edge.« less
Authors:
 [1] ;  [2] ;  [2] ;  [3] ;  [4] ;  [5] ;  [5] ; ORCiD logo [6] ;  [6] ;  [2]
  1. Universite Paris-Saclay (France). Laboratoire Charles Fabry, Institut d'Optique Graduate School, CNRS; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Center for X-ray Optics
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Center for X-ray Optics
  3. Universite Paris-Saclay (France). Laboratoire Charles Fabry, Institut d'Optique Graduate School, CNRS; Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  4. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  5. Universite Paris-Saclay (France). Laboratoire Charles Fabry, Institut d'Optique Graduate School, CNRS
  6. Institut des NanoSciences de Paris (France)
Publication Date:
Grant/Contract Number:
AC02-05CH11231; AC52-07NA27344
Type:
Accepted Manuscript
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 124; Journal Issue: 3; Journal ID: ISSN 0021-8979
Publisher:
American Institute of Physics (AIP)
Research Org:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS
OSTI Identifier:
1482536

Delmotte, Franck, Meyer-Ilse, Julia, Salmassi, Farhad, Soufli, Regina, Burcklen, Catherine, Rebellato, Jennifer, Jérome, Arnaud, Vickridge, Ian, Briand, Emrick, and Gullikson, Eric. Soft x-ray optical constants of sputtered chromium thin films with improved accuracy in the L and M absorption edge regions. United States: N. p., Web. doi:10.1063/1.5027488.
Delmotte, Franck, Meyer-Ilse, Julia, Salmassi, Farhad, Soufli, Regina, Burcklen, Catherine, Rebellato, Jennifer, Jérome, Arnaud, Vickridge, Ian, Briand, Emrick, & Gullikson, Eric. Soft x-ray optical constants of sputtered chromium thin films with improved accuracy in the L and M absorption edge regions. United States. doi:10.1063/1.5027488.
Delmotte, Franck, Meyer-Ilse, Julia, Salmassi, Farhad, Soufli, Regina, Burcklen, Catherine, Rebellato, Jennifer, Jérome, Arnaud, Vickridge, Ian, Briand, Emrick, and Gullikson, Eric. 2018. "Soft x-ray optical constants of sputtered chromium thin films with improved accuracy in the L and M absorption edge regions". United States. doi:10.1063/1.5027488.
@article{osti_1482536,
title = {Soft x-ray optical constants of sputtered chromium thin films with improved accuracy in the L and M absorption edge regions},
author = {Delmotte, Franck and Meyer-Ilse, Julia and Salmassi, Farhad and Soufli, Regina and Burcklen, Catherine and Rebellato, Jennifer and Jérome, Arnaud and Vickridge, Ian and Briand, Emrick and Gullikson, Eric},
abstractNote = {In this paper, we determine with improved accuracy the complex index of refraction n = 1 - δ + iβ of sputtered chromium thin films for photon energies ranging from 25 eV to 813 eV. These data include the first absolute measurements of the absorption fine structure near the Cr-L edge. First, we verified by combining Rutherford Backscattering Spectrometry and grazing-incidence x-ray reflectometry that the sputtered thin films were pure Cr with a density consistent with tabulated values. Then, we demonstrated that the Cr surface oxide layer remains stable when the samples are exposed to air for up to 4 years. The Cr absorption coefficient β was determined from the transmittance of freestanding Cr thin films with various thicknesses, measured at the ALS synchrotron radiation source. A model is proposed to correct the transmittance data from the spectral contamination of the source. Finally, we used the new β values, combined with theoretical and tabulated data from the literature, in order to calculate the δ values by the Kramers-Kronig relation. The improvement in the accuracy of β values is demonstrated by the f-sum rule. Finally, an additional validation of the new Cr optical constants (δ, β) is performed by comparing the simulated and experimental reflectance of a Cr/B4C multilayer mirror near the Cr-L2,3 edge.},
doi = {10.1063/1.5027488},
journal = {Journal of Applied Physics},
number = 3,
volume = 124,
place = {United States},
year = {2018},
month = {7}
}

Works referenced in this record:

Optical properties of metallic films for vertical-cavity optoelectronic devices
journal, January 1998
  • Rakić, Aleksandar D.; Djurišić, Aleksandra B.; Elazar, Jovan M.
  • Applied Optics, Vol. 37, Issue 22, p. 5271-5283
  • DOI: 10.1364/AO.37.005271

X-Ray Interactions: Photoabsorption, Scattering, Transmission, and Reflection at E = 50-30,000 eV, Z = 1-92
journal, July 1993
  • Henke, B. L.; Gullikson, E. M.; Davis, J. C.
  • Atomic Data and Nuclear Data Tables, Vol. 54, Issue 2, p. 181-342
  • DOI: 10.1006/adnd.1993.1013