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An ultrabright and monochromatic electron point source made of a LaB6 nanowire

Nature Nanotechnology volume 11, pages 273–279 (2016)Cite this article

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Abstract

Electron sources in the form of one-dimensional nanotubes and nanowires are an essential tool for investigations in a variety of fields, such as X-ray computed tomography, flexible displays, chemical sensors and electron optics applications. However, field emission instability and the need to work under high-vacuum or high-temperature conditions have imposed stringent requirements that are currently limiting the range of application of electron sources. Here we report the fabrication of a LaB6 nanowire with only a few La atoms bonded on the tip that emits collimated electrons from a single point with high monochromaticity. The nanostructured tip has a low work function of 2.07 eV (lower than that of Cs) while remaining chemically inert, two properties usually regarded as mutually exclusive. Installed in a scanning electron microscope (SEM) field emission gun, our tip shows a current density gain that is about 1,000 times greater than that achievable with W(310) tips, and no emission decay for tens of hours of operation. Using this new SEM, we acquired very low-noise, high-resolution images together with rapid chemical compositional mapping using a tip operated at room temperature and at 10-times higher residual gas pressure than that required for W tips.

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Figure 1: Nanofabrication of a LaB6 electron point source.
Figure 2: Electron optical characterization of the LaB6 NW field emitter.
Figure 3: Stability of field-induced electron emission.
Figure 4: A field emission SEM with a LaB6 nanowire electron point source.

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Acknowledgements

This work was partially supported by the Development of System and Technology for Advanced Measurement and Analysis, Japan Science and Technology Corporation (JST) and the Nanotechnology Network Project of the Ministry of Education, Culture, Sports, Science, and Technology (MEXT), Japan. The authors also wish to thank Hitachi High-Technologies Corporation for assistance in this project.

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Authors and Affiliations

  1. National Institute for Materials Science, Tsukuba, 305-0047, Ibaraki, Japan

    Han Zhang, Jie Tang, Jinshi Yuan, Yasushi Yamauchi, Taku T. Suzuki, Norio Shinya & Kiyomi Nakajima

  2. Graduate School of Pure and Applied Science, University of Tsukuba, Tsukuba, 305-8577, Ibaraki, Japan

    Jie Tang

  3. Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, 27599-3255, North Carolina, USA

    Lu-Chang Qin

Authors
  1. Han Zhang
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  4. Yasushi Yamauchi
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  5. Taku T. Suzuki
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  6. Norio Shinya
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Contributions

H.Z., J.T. and L.C.Q. conceived the idea of the study and performed data analysis. H.Z. carried out the main experiments. H.Z., J.T. and L.C.Q. wrote the manuscript. J.T. supervised the project. J.Y. participated in component fabrication. Y.Y. participated in component design and result analysis. T.T.S. participated in the electron energy analyser construction. K.N. carried out electron/ion beam fabrication. N.S. participated in data analysis.

Corresponding authors

Correspondence to Han Zhang or Jie Tang.

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The authors declare no competing financial interests.

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Zhang, H., Tang, J., Yuan, J. et al. An ultrabright and monochromatic electron point source made of a LaB6 nanowire. Nature Nanotech 11, 273–279 (2016). https://doi.org/10.1038/nnano.2015.276

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