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

Etsuo Akiba; Kouji Sakaki; Yumiko Nakamura

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 proceeding › Conference contribution

Abstract

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 LaNi_5-xMx (M=Al, Sn). Volume expansion and contraction can be accepted by introducing defects in the lattice without reducing the crystallite size.

Original language	English
Title of host publication	Advanced 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 pages	1
Publication status	Published - May 22 2006
Externally published	Yes
Event	2006 TMS Annual Meeting - San Antonio, TX, United States Duration: Mar 12 2006 → Mar 16 2006

Publication series

Name	TMS Annual Meeting
Volume	2006

Other

Other	2006 TMS Annual Meeting
Country/Territory	United States
City	San Antonio, TX
Period	3/12/06 → 3/16/06

All Science Journal Classification (ASJC) codes

Condensed Matter Physics
Mechanics of Materials
Metals and Alloys

Cite this

Defects formation in LaNi₅ and its related alloys with hydrogenation and dehydrogenation. / Akiba, Etsuo; Sakaki, Kouji; Nakamura, Yumiko.
Advanced 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. 2006. (TMS Annual Meeting; Vol. 2006).

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

Akiba, E, Sakaki, K & Nakamura, Y 2006, Defects formation in LaNi₅ and its related alloys with hydrogenation and dehydrogenation. in Advanced 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. TMS Annual Meeting, vol. 2006, 2006 TMS Annual Meeting, San Antonio, TX, United States, 3/12/06.

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