Relations between the localisation of the 5f electrons and the structure in AnTAl compounds (T element from the VIIIth group)
The MTAl compounds crystallise with two main structure types: ZrNiAl and MgZn(2). If M is a rare earth or a metal issued from the IVb(Th.) group, then the limit is located between Co and Ni. The structure of MTAl compounds is MgZn(2) with T = Mn, Fe, Co and ZrNiAl with T = Ni, Cu. This limit still exists with UTAl compounds but it is located on Fe. The systematic realised on AnTAl compounds shows a gradual shift of the limit from Fe to Co-Ni if An is successively replaced with U, Np, Pu. This shift is related to the progressive localisation of the 5f electrons. Evidence of this localisation is also observed in the evolution of the a parameter of the structure ZrNiAl. This is no longer the case with the evolution of the c parameter. The molecular volume of AnTAl compounds is influenced by the transition metal and actinides. Localisation of both actinide and transition metal is again apparent.
Bibliographic Reference: Paper presented: 23. Journées des Actinides, Bühlerhöhe (DE), April 20-23, 1993
Availability: Available from (1) as Paper EN 37672 ORA
Record Number: 199311486 / Last updated on: 1994-11-28
Original language: en
Available languages: en