---
OA_place: publisher
OA_type: hybrid
_id: '21525'
abstract:
- lang: eng
  text: We present a novel design for an ultracompact, passive light source capable
    of generating ultraviolet and X-ray radiation, based on the interaction of free
    electrons with the magnetic near-field of a ferromagnet. Our design is motivated
    by recent advances in the fabrication of nanostructures, which allow the confinement
    of large magnetic fields at the surface of ferromagnetic nanogratings. Using ab
    initio simulations and a complementary analytical theory, we show that highly
    directional, tunable, monochromatic radiation at high frequencies could be produced
    from relatively low-energy electrons within a tabletop design. The output frequency
    is tunable in the extreme ultraviolet to hard X-ray range via electron kinetic
    energies from 1 keV to 5 MeV and nanograting periods from 1 μm to 5 nm. The proposed
    radiation source can achieve the tunability and monochromaticity of current free-electron-driven
    sources (free-electron lasers, synchrotrons, and laser-driven undulators), yet
    with a significantly reduced scale, cost, and complexity. Our design could help
    realize the next generation of tabletop or on-chip X-ray sources.
article_processing_charge: No
article_type: letter_note
arxiv: 1
author:
- first_name: Sophie
  full_name: Fisher, Sophie
  last_name: Fisher
- first_name: Charles
  full_name: Roques-Carmes, Charles
  id: e2e68fc9-6505-11ef-a541-eb4e72cc3e82
  last_name: Roques-Carmes
- first_name: Nicholas
  full_name: Rivera, Nicholas
  last_name: Rivera
- first_name: Liang Jie
  full_name: Wong, Liang Jie
  last_name: Wong
- first_name: Ido
  full_name: Kaminer, Ido
  last_name: Kaminer
- first_name: Marin
  full_name: Soljačić, Marin
  last_name: Soljačić
citation:
  ama: Fisher S, Roques-Carmes C, Rivera N, Wong LJ, Kaminer I, Soljačić M. Monochromatic
    X-ray source based on scattering from a magnetic nanoundulator. <i>ACS Photonics</i>.
    2020;7(5):1096-1103. doi:<a href="https://doi.org/10.1021/acsphotonics.0c00121">10.1021/acsphotonics.0c00121</a>
  apa: Fisher, S., Roques-Carmes, C., Rivera, N., Wong, L. J., Kaminer, I., &#38;
    Soljačić, M. (2020). Monochromatic X-ray source based on scattering from a magnetic
    nanoundulator. <i>ACS Photonics</i>. American Chemical Society . <a href="https://doi.org/10.1021/acsphotonics.0c00121">https://doi.org/10.1021/acsphotonics.0c00121</a>
  chicago: Fisher, Sophie, Charles Roques-Carmes, Nicholas Rivera, Liang Jie Wong,
    Ido Kaminer, and Marin Soljačić. “Monochromatic X-Ray Source Based on Scattering
    from a Magnetic Nanoundulator.” <i>ACS Photonics</i>. American Chemical Society
    , 2020. <a href="https://doi.org/10.1021/acsphotonics.0c00121">https://doi.org/10.1021/acsphotonics.0c00121</a>.
  ieee: S. Fisher, C. Roques-Carmes, N. Rivera, L. J. Wong, I. Kaminer, and M. Soljačić,
    “Monochromatic X-ray source based on scattering from a magnetic nanoundulator,”
    <i>ACS Photonics</i>, vol. 7, no. 5. American Chemical Society , pp. 1096–1103,
    2020.
  ista: Fisher S, Roques-Carmes C, Rivera N, Wong LJ, Kaminer I, Soljačić M. 2020.
    Monochromatic X-ray source based on scattering from a magnetic nanoundulator.
    ACS Photonics. 7(5), 1096–1103.
  mla: Fisher, Sophie, et al. “Monochromatic X-Ray Source Based on Scattering from
    a Magnetic Nanoundulator.” <i>ACS Photonics</i>, vol. 7, no. 5, American Chemical
    Society , 2020, pp. 1096–103, doi:<a href="https://doi.org/10.1021/acsphotonics.0c00121">10.1021/acsphotonics.0c00121</a>.
  short: S. Fisher, C. Roques-Carmes, N. Rivera, L.J. Wong, I. Kaminer, M. Soljačić,
    ACS Photonics 7 (2020) 1096–1103.
date_created: 2026-03-30T12:22:47Z
date_published: 2020-04-01T00:00:00Z
date_updated: 2026-04-15T11:51:29Z
day: '01'
ddc:
- '530'
doi: 10.1021/acsphotonics.0c00121
extern: '1'
external_id:
  arxiv:
  - '1910.09629'
  pmid:
  - ' 32596415'
has_accepted_license: '1'
intvolume: '         7'
issue: '5'
keyword:
- X-ray sources
- free electrons
- nanostructure
- undulator
- synchrotron
- free-electron laser
language:
- iso: eng
license: https://creativecommons.org/licenses/by/4.0/
main_file_link:
- open_access: '1'
  url: https://doi.org/10.1021/acsphotonics.0c00121
month: '04'
oa: 1
oa_version: Published Version
page: 1096-1103
pmid: 1
publication: ACS Photonics
publication_identifier:
  eissn:
  - 2330-4022
publication_status: published
publisher: 'American Chemical Society '
quality_controlled: '1'
scopus_import: '1'
status: public
title: Monochromatic X-ray source based on scattering from a magnetic nanoundulator
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 7
year: '2020'
...
---
OA_type: closed access
_id: '371'
abstract:
- lang: eng
  text: The design and engineering of earth-abundant catalysts that are both cost-effective
    and highly active for water splitting are crucial challenges in a number of energy
    conversion and storage technologies. In this direction, herein we report the synthesis
    of Fe3O4@NiFexOy core-shell nanoheterostructures and the characterization of their
    electrocatalytic performance toward the oxygen evolution reaction (OER). Such
    nanoparticles (NPs) were produced by a two-step synthesis procedure involving
    the colloidal synthesis of Fe3O4 nanocubes with a defective shell and the posterior
    diffusion of nickel cations within this defective shell. Fe3O4@NiFexOy NPs were
    subsequently spin-coated over ITO-covered glass and their electrocatalytic activity
    toward water oxidation in carbonate electrolyte was characterized. Fe3O4@NiFexOy
    catalysts reached current densities above 1 mA/cm2 with a 410 mV overpotential
    and Tafel slopes of 48 mV/dec, which is among the best electrocatalytic performances
    reported in carbonate electrolyte.
acknowledgement: "This work was supported by the European Regional Development Funds
  and the Spanish MINECO project BOOSTER, TNT-FUELS, e-TNT, Severo Ochoa Program (MINECO,
  Grant SEV-2013-0295), and PEC?CO2. Z.L. thanks the China Scholarship Council for
  scholarship support. P.G. acknowledges the People Programme (Marie Curie Actions)
  of the FP7/2007-2013 European Union Program (TECNIOspring grant agreement no. 600388)
  and the Agency for Business Competitiveness of the Government of Catalonia, ACCIO.
  M.I. thanks AGAUR for Beatriu de Pinos postdoctoral grant (2013 BP-A00344).\r\n\r\n"
article_processing_charge: No
article_type: original
author:
- first_name: Zhishan
  full_name: Luo, Zhishan
  last_name: Luo
- first_name: Sara
  full_name: Márti Sánchez, Sara
  last_name: Márti Sánchez
- first_name: Raquel
  full_name: Nafria, Raquel
  last_name: Nafria
- first_name: Gihan
  full_name: Joshua, Gihan
  last_name: Joshua
- first_name: Maria
  full_name: De La Mata, Maria
  last_name: De La Mata
- first_name: Pablo
  full_name: Guardia, Pablo
  last_name: Guardia
- first_name: Christina
  full_name: Flox, Christina
  last_name: Flox
- first_name: Carlos
  full_name: Martínez Boubeta, Carlos
  last_name: Martínez Boubeta
- first_name: Konstantinos
  full_name: Simeonidis, Konstantinos
  last_name: Simeonidis
- first_name: Jordi
  full_name: Llorca, Jordi
  last_name: Llorca
- first_name: Joan
  full_name: Morante, Joan
  last_name: Morante
- first_name: Jordi
  full_name: Arbiol, Jordi
  last_name: Arbiol
- first_name: Maria
  full_name: Ibanez Sabate, Maria
  id: 43C61214-F248-11E8-B48F-1D18A9856A87
  last_name: Ibanez Sabate
  orcid: 0000-0001-5013-2843
- first_name: Andreu
  full_name: Cabot, Andreu
  last_name: Cabot
citation:
  ama: Luo Z, Márti Sánchez S, Nafria R, et al. Fe3O4@NiFexOy nanoparticles with enhanced
    electrocatalytic properties for oxygen evolution in carbonate electrolyte. <i>Applied
    Materials and Interfaces</i>. 2016;8(43):29461-29469. doi:<a href="https://doi.org/10.1021/acsami.6b09888">10.1021/acsami.6b09888</a>
  apa: Luo, Z., Márti Sánchez, S., Nafria, R., Joshua, G., De La Mata, M., Guardia,
    P., … Cabot, A. (2016). Fe3O4@NiFexOy nanoparticles with enhanced electrocatalytic
    properties for oxygen evolution in carbonate electrolyte. <i>Applied Materials
    and Interfaces</i>. American Chemical Society. <a href="https://doi.org/10.1021/acsami.6b09888">https://doi.org/10.1021/acsami.6b09888</a>
  chicago: Luo, Zhishan, Sara Márti Sánchez, Raquel Nafria, Gihan Joshua, Maria De
    La Mata, Pablo Guardia, Christina Flox, et al. “Fe3O4@NiFexOy Nanoparticles with
    Enhanced Electrocatalytic Properties for Oxygen Evolution in Carbonate Electrolyte.”
    <i>Applied Materials and Interfaces</i>. American Chemical Society, 2016. <a href="https://doi.org/10.1021/acsami.6b09888">https://doi.org/10.1021/acsami.6b09888</a>.
  ieee: Z. Luo <i>et al.</i>, “Fe3O4@NiFexOy nanoparticles with enhanced electrocatalytic
    properties for oxygen evolution in carbonate electrolyte,” <i>Applied Materials
    and Interfaces</i>, vol. 8, no. 43. American Chemical Society, pp. 29461–29469,
    2016.
  ista: Luo Z, Márti Sánchez S, Nafria R, Joshua G, De La Mata M, Guardia P, Flox
    C, Martínez Boubeta C, Simeonidis K, Llorca J, Morante J, Arbiol J, Ibáñez M,
    Cabot A. 2016. Fe3O4@NiFexOy nanoparticles with enhanced electrocatalytic properties
    for oxygen evolution in carbonate electrolyte. Applied Materials and Interfaces.
    8(43), 29461–29469.
  mla: Luo, Zhishan, et al. “Fe3O4@NiFexOy Nanoparticles with Enhanced Electrocatalytic
    Properties for Oxygen Evolution in Carbonate Electrolyte.” <i>Applied Materials
    and Interfaces</i>, vol. 8, no. 43, American Chemical Society, 2016, pp. 29461–69,
    doi:<a href="https://doi.org/10.1021/acsami.6b09888">10.1021/acsami.6b09888</a>.
  short: Z. Luo, S. Márti Sánchez, R. Nafria, G. Joshua, M. De La Mata, P. Guardia,
    C. Flox, C. Martínez Boubeta, K. Simeonidis, J. Llorca, J. Morante, J. Arbiol,
    M. Ibáñez, A. Cabot, Applied Materials and Interfaces 8 (2016) 29461–29469.
date_created: 2018-12-11T11:46:05Z
date_published: 2016-11-02T00:00:00Z
date_updated: 2026-05-13T13:32:06Z
day: '02'
doi: 10.1021/acsami.6b09888
extern: '1'
external_id:
  pmid:
  - '27730808'
intvolume: '         8'
issue: '43'
keyword:
- nanoparticle
- iron oxide
- magnetite
- core−shell nanostructure
- electrocatalysts
- oxygen evolution reaction
- OER
language:
- iso: eng
month: '11'
oa_version: None
page: 29461 - 29469
pmid: 1
publication: Applied Materials and Interfaces
publication_identifier:
  eissn:
  - 1944-8252
  issn:
  - 1944-8244
publication_status: published
publisher: American Chemical Society
publist_id: '7458'
quality_controlled: '1'
scopus_import: '1'
status: public
title: Fe3O4@NiFexOy nanoparticles with enhanced electrocatalytic properties for oxygen
  evolution in carbonate electrolyte
type: journal_article
user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd
volume: 8
year: '2016'
...