Positron annihilation study on hafnium specimens given various treatments = 양전자소멸을 이용한 하프늄의 가공에 따른 격자결함 및 수소와의 반응에 관한 연구

Positron annihilation measurements for annealed, cold-worked, annealedquenched, and cold-worked and hydrogen-charged hafnium specimens were made to investigate kinds of defects existing in the specimens, interaction between defects and hydrogen atoms and behavior of defects on isochronal annealing. Lifetime and Doppler broadening lineshape measurements for cold-worked and hydrogen-charged specimens indicated that a new kind of positron traps as well as dislocations are produced during hydrogen charging. It was inferred that the new positron traps formed are hydrogen bubbles or voids. Doppler broadening lineshape parameter P/W for cold-worked hafnium specimens increased first and then decreased due to the proton screeing of some defects, and this sequence was repeated when their hydrogen-charging was continued. Positron annihilation characteristics and microhardness of cold-worked, and cold-worked and hydrogen-charged hafnium specimens isochronally annealed were compared to study recovery and recrystallization stages of hafnium specimens. The general trend observed was an increase of the positron lifetime after hydrogenation. It was inferred that this increase in lifetime is attributed to the covalent nature of the Hf-H bond of hafnium hydride.
Advisors
Yoon, Young-Kuresearcher윤용구researcher
Publisher
한국과학기술원
Issue Date
1992
Identifier
60251/325007 / 000891003
Language
eng
Description

학위논문(석사) - 한국과학기술원 : 원자력공학과, 1992.2, [ iii, 51 p. ]

URI
http://hdl.handle.net/10203/49048
Link
http://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=60251&flag=t
Appears in Collection
NE-Theses_Master(석사논문)
Files in This Item
There are no files associated with this item.
  • Hit : 95
  • Download : 0
  • Cited 0 times in thomson ci

qr_code

  • mendeley

    citeulike


rss_1.0 rss_2.0 atom_1.0