ウエダ　ヨシオ   Ueda Yoshio   上田　良夫    所属   追手門学院大学  理工学部 電気電子工学科    職種   教授
言語種別	英語
発行・発表の年月	2017/04
形態種別	論文
査読	査読あり
標題	Comparison between helium plasma induced surface structures in group 5 (Nb, Ta) and group 6 elements (Mo, W)
執筆形態	共著・編著（代表編著を除く）
掲載誌名	JOURNAL OF APPLIED PHYSICS
掲載区分	国外
出版社・発行元	AMER INST PHYSICS
巻・号・頁	121(15)
著者・共著者	K. Omori,A. M. Ito,K. Shiga,N. Yamashita,K. Ibano,H. T. Lee,Y. Ueda
概要	Group 5 elements (niobium and tantalum) and group 6 elements (molybdenum and tungsten) were exposed to helium plasma, and the resulting surface structures were observed by electron microscopy. Group 5 elements showed hole structures, where the size of the holes ranged from several tens of nm to a few hundred nm in diameter, while group 6 elements showed fiber-like structures. As a first step in understanding such differences, the difference in helium agglomeration energies and changes in the stress tensor as a function of the number of He atoms at interstitial sites were investigated for each element using density functional theory. The calculations revealed that helium atoms prefer to agglomerate in both of these groups. However, helium in group 6 elements can agglomerate more easily than group 5 elements due to higher binding energy.
DOI	10.1063/1.4981128
ISSN	0021-8979/1089-7550