Electronic properties of Pu 19 Os simulating β-Pu: the strongly correlated Pu phase

• Published in: Journal of physics. Condensed matter 2018-02, Vol.30 (8), p.085601
• Main Authors: Havela, L, Mašková, S, Kolorenč, J, Colineau, E, Griveau, J-C, Eloirdi, R
• Format: Article
• Language: English
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/1361-648X/aaa520

We established the basic electronic properties of ζ-Pu Os, which is a close analogue to β-Pu, and its low-temperature variety, η-Pu Os. Their magnetic susceptibility is 15% higher than for δ-Pu. A specific heat study of ζ-Pu Os shows a soft lattice similar to δ-Pu, leading to a low Debye temperature Θ   =  101 K. The linear electronic coefficient γ related to the quasiparticle density of states at the Fermi level points to a higher value, 55  ±  2 mJ (mol Pu K ) , compared to 40 mJ (mol K ) for δ-Pu. The results confirm that β-Pu is probably the most strongly correlated Pu phase, as had been indicated by resistivity measurements. The volume and related Pu-Pu spacing is clearly not the primary tuning parameter for Pu metal, as the β-Pu density stands close to the ground-state α-phase and is much higher than that for δ-Pu. The η-Pu Os phase has a record γ-value of 74  ±  2 mJ (mol Pu K ) . The enhancement is not reproduced by LDA+DMFT calculations in the fcc structure, which suggests that multiple diverse sites can be the key to the understanding of β-Pu.