Signatures of non-integer 5f occupancy in Pu systems: Magnetic properties and photoelectron spectroscopy studies

0323227 - FZÚ 2009 RIV US eng C - Konferenční příspěvek (zahraniční konf.)
Havela, L. - Shick, Alexander - Gouder, T. - Wastin, F. - Rebizant, J.
Signatures of non-integer 5f occupancy in Pu systems: Magnetic properties and photoelectron spectroscopy studies.
[Variabilita 5f stavů ve systémech obsahujích Pu.]
Actinides 2008 - Basic Science, Applications, and Technology. Warrendale, PA: Materials Research Society, 2008 - (Shuh, D.; Chung, B.; Albrecht-Schmitt, T.; Gouder, T.; Thompson, J.), s. 241-247. Materials Research Society Symposium Proceedings, NN, 1104. ISBN 978-1-60511-074-5.
[Actinides 2008-Basic Science, Applications, and Technology. San Francisco (US), 24.03.2008-28.03.2008]
Grant CEP: GA MŠMT OC 144; GA ČR GA202/07/0644
Výzkumný záměr: CEZ:AV0Z10100520
Klíčová slova: electronic sructure * photoemission * magnetism * strong electron correlations
Kód oboru RIV: BM - Fyzika pevných látek a magnetismus

Very diverse Pu compounds exhibit strikingly universal features in their valence-band photoemission (PES) spectra. The conjecture that such features represent the 5f5 final state multiplet has been corroborated by LDA+Hubbard I calculations, meaning that the ground state has a mixed 5f5-5f6 character. Later on, more elaborated DMFT techniques (one crossing approximation, QMC) led to similar conclusions, providing quantitative explanation of such intermeate-valent situation in more details. Analogies in PES spectra of d-Pu and other Pu systems suggest that the situation envisaged for d-Pu is relevant for a large group of Pu compounds. Here we show that the around mean field LDA+U in conjunction with the Hubbard I approximation, which describes well the non-magnetic ground state for d-Pu, captures in reality properties of a large group of Pu (as well as e.g. Am) compounds, reproducing correctly the onset of magnetism and size of magnetic moments.

Studium fotoelektronových spekter. Zjistili jsme, že podmínkou pro vznik magnetizace ve slitinách a sloučeninách plutonia je hybridizace, která dovolí snížit počet 5f elektronů.
Trvalý link: http://hdl.handle.net/11104/0171251