Electronic structure and Fermi surface of paramagnetic and antiferromagnetic UPt2Si2
2012 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 86, no 7, 075104- p.Article in journal (Refereed) Published
We report density functional theory-based calculations of the electronic structure and Fermi surface properties of the intermetallic uranium compound UPt2Si2, which orders antiferromagnetically at TN=32 K with a total magnetic moment of 2μB/U-atom and exhibits a moderate mass enhancement in the specific-heat coefficient. Our investigation is carried out using relativistic, full-potential band-structure methods within the framework of the local spin density approximation (LSDA), the LSDA with orbital polarization correction (LSDA+OPC), and the LSDA supplemented with an additional Hubbard U (LSDA+U). We find that the LSDA+OPC scheme predicts the total magnetic moment in best agreement with experiment; from this we infer that the 5f electrons in UPt2Si2 are orbitally polarized, mostly itinerant, and exhibit only a slight tendency toward localization. Our total energy calculations predict UPt2Si2 to form in the CaBe2Si2 (P4/nmm) structure, in contrast to URu2Si2 (ThCr2Si2: I4/mmm). The theoretical Fermi surfaces are also studied for the nonmagnetic and antiferromagnetic phases with the employed computational schemes and are found to be quasi-two-dimensional. At the antiferromagnetic transition, the Fermi surface is found to become more two-dimensional with small regions of gapping.
Place, publisher, year, edition, pages
2012. Vol. 86, no 7, 075104- p.
IdentifiersURN: urn:nbn:se:uu:diva-180272DOI: 10.1103/PhysRevB.86.075104ISI: 000307272000001OAI: oai:DiVA.org:uu-180272DiVA: diva2:549150