Gutzwiller-type approach of the size-dependent valence change in small Pr aggregates
- Laboratoire de Physique des Solides, Universite Paris-Sud, 91405 Orsay, France (FR)
We give a theoretical approach to the valence change in small Pr{sub {ital n}} aggregates (transition: 4{ital f}{sup 3}(5{ital d}6{ital s}){sup 2}{r arrow}4{ital f}{sup 2}(5{ital d}6{ital s}){sup 3}), our study limited to {ital n}{le}4. The quantum-mechanics problem (Anderson Hamiltonian) exhibits various difficulties: {ital f}-valence mixing and strong intra-atomic {ital f} correlations. For dealing with this problem we use an extension to the mixed-band systems of the Gutzwiller method. The extension is detailed and controlled by an application to the Hubbard {ital s} chain, for which the exact solution is known. As the number of {ital f} electrons and sites of our Pr{sub {ital n}} system is relatively small, we take into account the full {ital f} degeneracy. We find the transition for {ital n}=3, which is close to the experimental result, {ital n}=5. A physical explanation of the phenomenon is proposed.
- OSTI ID:
- 6866029
- Journal Information:
- Physical Review, B: Condensed Matter; (USA), Vol. 41:7; ISSN 0163-1829
- Country of Publication:
- United States
- Language:
- English
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