Influence of different temperatures on morphology and chemical state of the surface-active layer of scandium-tungsten cathode

doi:10.1016/j.ijrmhm.2022.105958

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	Influence of different temperatures on morphology and chemical state of the surface-active layer of scandium-tungsten cathode
	Cheng, Yin 1,2; Wang, ShiYang 1; Sun, Yuan 1; Yang, YanHong 1; Zhou, YiZhou 1
刊名	INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
	2022-11-01
卷号	108 页码:9
关键词	Electronic materials Active layer Valence states Work function Scandium-tungsten (Sc-W) cathodes
ISSN号	0263-4368
DOI	10.1016/j.ijrmhm.2022.105958
通讯作者	Sun, Yuan(yuansun@imr.ac.cn) ; Zhou, YiZhou(yzzhou@imr.ac.cn)
英文摘要	Scandium-tungsten (Sc-W) cathodes have garnered a lot of research attention due to their high emission current density. Herein, the cathode working environment is simulated by heating in a vacuum chamber, and scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) are used to study the surface morphology and chemical oxidation states in the temperature range of 25 degrees C to 1300 degrees C. The results reveal that the surface of the tungsten matrix is obviously recrystallized with increasing temperature. Moreover, the scandium oxide becomes globular and clear depressions or holes occur in the aggregation region of the rare-earth oxide at the grain boundaries. The work function is measured by the Richardson method at room temperature, 1000 degrees C, and 1300 degrees C and is found to be 2.77, 2.72, and 2.88 eV, respectively. The work function of the cathode initially decreases with increasing temperature, followed by a gradual increase. This is due to the fact that active substances such as scandium oxide are severely lost at high temperatures, destroying the surface structure of the sample. As the Sc/W value decreases, the rate of depletion of active material from the surface is greater than the rate of replenishment of material to the surface.
资助项目	National Science and Technology Major Project[J2019 -VI -0018-0133] ; Key Specialized Research and Development Breakthrough-unveiling and Commanding the Special Project Program in Liaoning Province[2021JH15] ; Transformation of scientific and technological achievements[20-203-5-19]
WOS研究方向	Materials Science ; Metallurgy & Metallurgical Engineering
语种	英语
出版者	ELSEVIER SCI LTD
WOS记录号	WOS:000841249200001
资助机构	National Science and Technology Major Project ; Key Specialized Research and Development Breakthrough-unveiling and Commanding the Special Project Program in Liaoning Province ; Transformation of scientific and technological achievements
内容类型	期刊论文
源URL	[http://ir.imr.ac.cn/handle/321006/174497]
专题	金属研究所_中国科学院金属研究所
通讯作者	Sun, Yuan; Zhou, YiZhou
作者单位	1.Chinese Acad Sci, Inst Met Res, Shi Changxu Innovat Ctr Adv Mat, Shenyang 110016, Peoples R China 2.Univ Sci & Technol China, Sch Mat Sci & Engn, Shenyang 110016, Peoples R China
推荐引用方式 GB/T 7714	Cheng, Yin,Wang, ShiYang,Sun, Yuan,et al. Influence of different temperatures on morphology and chemical state of the surface-active layer of scandium-tungsten cathode[J]. INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS,2022,108:9.
APA	Cheng, Yin,Wang, ShiYang,Sun, Yuan,Yang, YanHong,&Zhou, YiZhou.(2022).Influence of different temperatures on morphology and chemical state of the surface-active layer of scandium-tungsten cathode.INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS,108,9.
MLA	Cheng, Yin,et al."Influence of different temperatures on morphology and chemical state of the surface-active layer of scandium-tungsten cathode".INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS 108(2022):9.