Physical Operating Principles of Palladium–Barium Cathodes of Microwave Devices

Капустин, В. И.; Li, I. P.; Shumanov, A. V.; Moskalenko, S. O.; Bush, A. A.; Lebedinskiǐ, Yu. Yu.

doi:10.1134/s1063784219050086

Cited by 8 publications

(3 citation statements)

References 3 publications

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“…The binary constitutional diagrams of BaO and oxides of Са, Al, Sc, W, Re, Os, Pd, and Ni are eutectic, in which there are no ranges of mutual solubility of the oxides, although the solubility of different elements in BaO cannot be zero in principle. In publications [5][6][7], by optical spectroscopy and electron spectroscopy for chemical analysis (ESCA), the effect of Са, Al, W, and Sc microimpurities and the synergistic effect of Са and Sr microimpurities (microimpurities of s and р elements) on the electronic structure of BaO crystallites was revealed. The effect of microimpurities of Ni (with the valence of +2.1-2.2) and Sc (with the valence of +3), whose ion radii are 0.54 and 0.60 of the Ва ion radius, on the offset of the valence band of BaO crystallites and ordering of oxygen vacancies in the bulk of crystallites are also demonstrated.…”

Section: Valence Bandmentioning

confidence: 99%

“…Earlier, with nickel oxide [5], dispenser-type and scandate [6], and palladium-barium [7] cathodes, it was demonstrated that atoms of the cathode components (Са, Sr, Ni, W, Al, Sc, Pd) are dissolved in BaO crystallites, which significantly affects the electronic structure of BaO crystallites and, correspondingly, their emission properties. In formation of the electronic structure of BaO crystallites in multicomponent cathodes, the main factors determining the character of this structure are the size, valence, and electronic factors of doping elements.…”

Section: Introductionmentioning

confidence: 99%

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Physical Mechanism of Operation of Osmium-Coated Cathodes of Microwave Devices

Капустин

Li²,

Moskalenko³

et al. 2021

Inorg. Mater. Appl. Res.

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The electronic structure and physical chemistry of an osmium-coated cathode are determined, and the physical mechanism of the effect of osmium on the electronic structure and emission properties of a dispenser cathode is investigated. The studies are carried out by optical spectroscopy, electron spectroscopy for chemical analysis, and electron energy-loss spectroscopy. The emission properties of standard dispenser cathodes are determined by oxygen vacancies in BaO crystallites; the surface oxygen vacancies form acceptor surface states, which is accompanied by upward bending of the oxide energy bands. In osmium-coated dispenser cathodes, osmium atoms are dissolved in BaO crystallites and form extra donor surface states at the surface of crystallites, which results in downward bending of the oxide energy bands and, correspondingly, a decrease in the work function of the cathode material.

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Section: Valence Bandmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Physical Mechanism of Operation of Osmium-Coated Cathodes of Microwave Devices

Капустин

Li²,

Moskalenko³

et al. 2021

Inorg. Mater. Appl. Res.

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“…Эти образцы после термической активации в высоком вакууме обладают довольно высоким (~2.6) коэффициентом вторичной электронной эмиссии σ и низкой (~2.3 эВ) работой выхода еϕ. В последние годы особый интерес представляют сплавные катоды с наноразмерными слоями, и поэтому существенно увеличились требования к размерам, однородности состава и срока службы этих катодов [1][2][3][4][5][6].…”

Section: Introductionunclassified

Эмиссионные свойства Mo, Pd и Pd-Ba при имплантации ионов бария и кислорода

Донаев¹,

Umirzakov²,

Ширинов³

et al. 2021

УФЖ

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Исследовано влияние ионного легирования на вторично-эмиссионные характеристики Mo, Pd и сплава Pd-Ва. Установлено, что в результате легирования ионами бария с низкой энергией в приповерхностном слое Pd образуется интерметаллическое соединение типа Pd-Ва. Образование химического соединения подложки с легирующей примесью способствует значительному (в 3 раза) росту коэффициента вторичной электронной эмиссии (ВЭЭ). Обнаружено, что образцы Pd и Pd-Ва после легирования большой дозой ионов Ва+ обладают почти одинаковыми вторично-эмиссионными параметрами. Легирование Pd-Ba сначала ионами бария, затем ионами кислорода с энергией Е0≤1 кэВ приводит к существенному увеличению коэффициента вторично-электронной эмиссии (ВЭЭ). В случае имплантации ионов Ва+ в Мо не наблюдается образования химической связи между атомами Ва и Мо. Поэтому эмиссионная эффективность в ионнолегированном слое увеличивается незначительно (1.3 раза) и увеличение максимального значения коэффициента вторичной электронной эмиссии σmax объясняется в основном уменьшением значения работы выхода eφ.

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Cathodes in magnetrons: A review

Liu,

Yang,

Sun

et al. 2024

MetalMat

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Magnetron is currently one kind of the most widely used vacuum electronic devices. The cathode, as the electronic source of the device, is the core of magnetrons. With the development of magnetrons, the requirements for cathode performance are also increasing, including thermal electron emission and secondary electron emission performance. This article reviews the development history of cathodes used in magnetrons, discusses the performance and application fields of various cathodes, and the relationship between performance and structure. However, there are still certain problems with various cathode materials that make it difficult to truly cover all magnetrons. The ongoing challenges relating to the magnetron cathodes have been discussed in this paper.

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Physical Operating Principles of Palladium–Barium Cathodes of Microwave Devices

Cited by 8 publications

References 3 publications

Physical Mechanism of Operation of Osmium-Coated Cathodes of Microwave Devices

Physical Mechanism of Operation of Osmium-Coated Cathodes of Microwave Devices

Эмиссионные свойства Mo, Pd и Pd-Ba при имплантации ионов бария и кислорода

Cathodes in magnetrons: A review

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