Physical Operating Principles of Palladium–Barium Cathodes of Microwave Devices

High-resolution X-ray diffraction method (XRD) is used to determine sizes and crystallographic orientation of the nanocrystallites of the Pd and Pd 5 Ba phases in palladium–barium cathode. Electron spectroscopy for chemical analysis (ESCA) is used to study Ba and Pd chemical states in cathode materi...

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Bibliographic Details
Published inTechnical physics Vol. 64; no. 5; pp. 720 - 729
Main Authors Kapustin, V. I., Li, I. P., Shumanov, A. V., Moskalenko, S. O., Bush, A. A., Lebedinskii, Yu. Yu
Format Journal Article
LanguageEnglish
Published Moscow Pleiades Publishing 01.05.2019
Springer Nature B.V
Subjects
Activation
BARIUM
BARIUM OXIDES
CATHODES
Cathodic dissolution
CHEMICAL ANALYSIS
CHEMICAL STATE
Classical and Continuum Physics
CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY
Crystallites
CRYSTALLOGRAPHY
DIFFRACTION METHODS
Dissolution
Electrode materials
Electron energy loss spectroscopy
EMISSION
Energy dissipation
ENERGY-LOSS SPECTROSCOPY
GRAIN ORIENTATION
INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
Lattice vacancies
MICROWAVE RADIATION
NANOCRYSTALS
Organic chemistry
OXYGEN
PALLADIUM
Phase composition
Physical Electronics
Physics
Physics and Astronomy
Spectrum analysis
THIN FILMS
VACANCIES
X-RAY DIFFRACTION
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Summary:High-resolution X-ray diffraction method (XRD) is used to determine sizes and crystallographic orientation of the nanocrystallites of the Pd and Pd 5 Ba phases in palladium–barium cathode. Electron spectroscopy for chemical analysis (ESCA) is used to study Ba and Pd chemical states in cathode material and determine the phase composition including dissolved microimpurities in the phases. The comparison of the XRD and ESCA data makes it possible to reveal effects related to the formation of the BaO crystallites in the cathode material, which are responsible for the emission properties. Electron-energy loss spectroscopy is used to determine the concentration of oxygen vacancies in the BaO crystallites that are formed in the cathode material due to activation. An original crystallite model of the working palladium–barium cathodes that is based on the results of this work may serve as an alternative to the known film model and makes it possible to optimize technology of cathode fabrication and activation.
ISSN:1063-7842
1090-6525
DOI:10.1134/S1063784219050086