The Mott-Like Transition Between Plutonium and Americium

The Mott-Like Transition Between Plutonium and Americium 

Whereas there are experimental evidences for the band behaviour of 5 f electrons up to plutonium (Z = 94) (see Table 3), the same criteria show that suddenly americium (Z = 95) behaves like a normal lanthanide having well localized 5f electrons ( and Chap. C)  

It can be stated that up to plutonium, 5 f electrons are in the conduction band and have no magnetic moment from americium on, 5f electrons are localized and carry a magnetic moment. 

forgetting about the superimposed normal 6 d-7s conduction band, there is a transition from a non-magnetic 5 f metal to a magnetic 5 f insulator (americium itself being non-magnetic only because J = 0). 

To put it on a more quantitative basis, Johansson uses the expression for the critical point of the Mott transition as reformulated by Hubbard in terms of the bandwidth W[ and the polar state formation energy Uh (or effective intra-atomic correlation) (Eq. (36)). 

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