Detail publikace

Cleaning of tungsten tips for subsequent use as cold field emitters or STM probes

KOŠELOVÁ, Z. HORÁKOVÁ, L. BURDA, D. ALLAHAM, M. KNÁPEK, A. FOHLEROVÁ, Z.

Originální název

Cleaning of tungsten tips for subsequent use as cold field emitters or STM probes

Typ

článek v časopise ve Web of Science, Jimp

Jazyk

angličtina

Originální abstrakt

This study investigates the crucial process of cleaning cold field emission electron emitters and scanning tunnel microscopy (STM) probes, particularly focusing on tungsten tips. The cleanliness of these tips is essential for maintaining optimal cathode properties, preventing impurities that can significantly affect the emission process. Various cleaning methods, including macroetching, ammonia cleaning, and hydrofluoric acid (HF) cleaning were explored and compared by scanning electron microscopy. The macroetching method, involving a mixture of hydrochloric acid, nitric acid, and hydrogen fluoride, proved to be too reactive, causing significant material removal and altering the tip's structure. Ammonia cleaning did not significantly improve or harm the samples. However, oxide islands appeared in some areas, suggesting the potential formation of ammonium tungsten oxide. HF cleaning, specifically at 20% and 50% concentrations, demonstrated effectiveness in removing tungsten oxides without damaging the tip. Pre-cleaning with water and ethanol proved beneficial for subsequent HF refinement. Results suggest that HF is the most suitable method for oxide removal but a rinse with water is essential for removing residual sodium hydroxide. To maintain optimal properties, it is crucial to apply a less reactive layer quickly or transfer the tips to a water/ethanol bath to prevent oxidation.

Klíčová slova

STM probes, field emission, cleaning procedure, tungsten tip, FEM

Autoři

KOŠELOVÁ, Z.; HORÁKOVÁ, L.; BURDA, D.; ALLAHAM, M.; KNÁPEK, A.; FOHLEROVÁ, Z.

Vydáno

31. 1. 2024

Nakladatel

FEI STU

Místo

Bratislava

ISSN

1339-309X

Periodikum

Journal of Electrical Engineering

Ročník

75

Číslo

1

Stát

Slovenská republika

Strany od

41

Strany do

46

Strany počet

6

URL

http://iris.elf.stuba.sk/JEEEC/data/pdf/1_124-06.pdf

BibTex

@article{BUT187804,
  author="Zuzana {Košelová} and Lenka {Horáková} and Daniel {Burda} and Mohammad Mahmoud {Allaham} and Alexandr {Knápek} and Zdenka {Fohlerová}",
  title="Cleaning of tungsten tips for subsequent use as cold field emitters or STM probes",
  journal="Journal of Electrical Engineering",
  year="2024",
  volume="75",
  number="1",
  pages="41--46",
  doi="10.2478/jee-2024-0006",
  issn="1339-309X",
  url="http://iris.elf.stuba.sk/JEEEC/data/pdf/1_124-06.pdf"
}