Structure of LaNi<sub>3.8</sub>AlMn<sub>0.2</sub>D<sub>3.2</sub> Compound Studied by Neutron Powder Diffraction

Abstract

The intermetallic alloy LaNi3.8AlMn0.2 and its deuteride LaNi3.8AlMn0.2D3.2 were studied by neutron powder diffraction. The experimental results show that the crystal structure of LaNi3.8AlMn0.2 is CaCu5 type with the hexagonal P6/mmm space group, the substituted Al atoms occupy 2c and 3g sites, while Mn atoms are only located on the 3g sites. For the corresponding deuteride LaNi3.8AlMn0.2D3.2, the P6/mmm space group gives the best refinement, but D atoms enter two interstitial sites 6m and 12n.