Defects formation in LaNi5 and its related alloys with hydrogenation and dehydrogenation

Etsuo Akiba, Kouji Sakaki, Yumiko Nakamura

Research output: Chapter in Book/Report/Conference proceedingConference contribution


With hydrogenation and dehydrogenation, lattice of hydrogen absorbing alloys expands and contracts in 20 to 30 % in volume. Defects are expected to be introduced into the lattice to relax the strain energy that is generated by volume expansion and contraction. We have studied defect formation into the lattice of LaNi5 and related alloys using in-situ diffraction and positron lifetime measurements. In the lattice of LaNi52, a large amount of defects such as dislocations and vacancies was introduced at the first hydrogenation. Once defects were introduced, they were not relaxed at the working temperature of the alloys. Using diffraction method, we measured the size of crystallite before and after hydrogenation. The crystallite size did not changed with hydrogenation in all the alloy studied; LaNi5 and LaNi5-xMx (M=Al, Sn). Volume expansion and contraction can be accepted by introducing defects in the lattice without reducing the crystallite size.

Original languageEnglish
Title of host publicationAdvanced Materials for Energy Conversion III - A Symposium in Honor of Drs. Gary Sandrock, Louis Schlapbach and Seijirau Suda for Lifetime Achievements in Metal Hydride Research and Development
Number of pages1
Publication statusPublished - May 22 2006
Externally publishedYes
Event2006 TMS Annual Meeting - San Antonio, TX, United States
Duration: Mar 12 2006Mar 16 2006

Publication series

NameTMS Annual Meeting


Other2006 TMS Annual Meeting
Country/TerritoryUnited States
CitySan Antonio, TX

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Mechanics of Materials
  • Metals and Alloys


Dive into the research topics of 'Defects formation in LaNi5 and its related alloys with hydrogenation and dehydrogenation'. Together they form a unique fingerprint.

Cite this