Experimental investigation and thermodynamic reassessment of La-Ni and LaNi5-H systems

► La-Ni binary phase diagram was thermodynamically assessed taking into account La5Ni19 phase. ► Phase relationship of LaNi5-H vertical section was thermodynamically optimized. ► Peritectic reaction of L+LaNi5→La5Ni19 took place at 1276 K. ► LaNi5H7 decomposed at 343 and 379 K under 1 and 3 MPa, respectively.