Heat content and heat of formation measurements of RNi5 ± x alloys (R ≡ La, Ce, Pr or Nd) and heat balance in a reduction-diffusion process

K. Yamaguchi, D. Y. Kim, M. Ohtsuka, K. Itagaki

Research output: Contribution to journalArticle

19 Citations (Scopus)


The heat contents of the LaNi5.25, CeNi5.13, PrNi4.65 and NdNi5.85 alloys were measured over the temperature range 800-1400 K using a drop calorimeter. The heat content and heat capacity equations were derived using the Shomate function. The heats of formation of these alloys were determined at 773 K from the heats of dissolution of these compounds and their components in a liquid tin solvent using a Calvet-type solution calorimeter. Heat balance was calculated for a reduction-diffusion process to make the RNi5 powders directly for use as hydrogen storage media by reducing the rare earth resources with metallic calcium, magnesium and lithium.

Original languageEnglish
Pages (from-to)161-168
Number of pages8
JournalJournal of Alloys and Compounds
Issue number1-2
Publication statusPublished - 1995 Apr 15



  • Formation measurements
  • Heat balance
  • Heat content
  • Reduction-diffusion

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

Cite this