In-situ observation of field-induced nano-protrusion growth on a carbon-coated tungsten nanotip

Fuente: arXiv
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Main Authors: Meng, Guodong, Li, Yimeng, Koitermaa, Roni Aleksi, Zadin, Veronika, Cheng, Yonghong, Kyritsakis, Andreas
Format: Preprint
Published: 2024
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author Meng, Guodong
Li, Yimeng
Koitermaa, Roni Aleksi
Zadin, Veronika
Cheng, Yonghong
Kyritsakis, Andreas
author_facet Meng, Guodong
Li, Yimeng
Koitermaa, Roni Aleksi
Zadin, Veronika
Cheng, Yonghong
Kyritsakis, Andreas
contents Nano-protrusion (NP) on metal surface and its inevitable contamination layer under high electric field is often considered as the primary precursor that leads to vacuum breakdown, which plays an extremely detrimental effect for high energy physics equipment and many other devices. Yet, the NP growth has never been experimentally observed. Here, we conduct field emission (FE) measurements along with in-situ Transmission Electron Microscopy (TEM) imaging of an amorphous-carbon (a-C) coated tungsten nanotip at various nanoscale vacuum gap distances. We find that under certain conditions, the FE current-voltage (I-V) curves switch abruptly into an enhanced-current state, implying the growth of an NP. We then run field emission simulations, demonstrating that the temporary enhanced-current I-V is perfectly consistent with the hypothesis that a NP has grown at the apex of the tip. This hypothesis is also confirmed by the repeatable in-situ observation of such a nano-protrusion and its continued growth during successive FE measurements in TEM. We tentatively attribute this phenomenon to field-induced biased diffusion of surface a-C atoms, after performing a finite element analysis that excludes the alternative possibility of field-induced plastic deformation.
format Preprint
id arxiv_https___arxiv_org_abs_2403_11794
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle In-situ observation of field-induced nano-protrusion growth on a carbon-coated tungsten nanotip
Meng, Guodong
Li, Yimeng
Koitermaa, Roni Aleksi
Zadin, Veronika
Cheng, Yonghong
Kyritsakis, Andreas
Materials Science
Mesoscale and Nanoscale Physics
Applied Physics
Nano-protrusion (NP) on metal surface and its inevitable contamination layer under high electric field is often considered as the primary precursor that leads to vacuum breakdown, which plays an extremely detrimental effect for high energy physics equipment and many other devices. Yet, the NP growth has never been experimentally observed. Here, we conduct field emission (FE) measurements along with in-situ Transmission Electron Microscopy (TEM) imaging of an amorphous-carbon (a-C) coated tungsten nanotip at various nanoscale vacuum gap distances. We find that under certain conditions, the FE current-voltage (I-V) curves switch abruptly into an enhanced-current state, implying the growth of an NP. We then run field emission simulations, demonstrating that the temporary enhanced-current I-V is perfectly consistent with the hypothesis that a NP has grown at the apex of the tip. This hypothesis is also confirmed by the repeatable in-situ observation of such a nano-protrusion and its continued growth during successive FE measurements in TEM. We tentatively attribute this phenomenon to field-induced biased diffusion of surface a-C atoms, after performing a finite element analysis that excludes the alternative possibility of field-induced plastic deformation.
title In-situ observation of field-induced nano-protrusion growth on a carbon-coated tungsten nanotip
topic Materials Science
Mesoscale and Nanoscale Physics
Applied Physics
url https://arxiv.org/abs/2403.11794