Gallium substitution in the transuranium superconductor PuCoGa.sub.5./sub.

0498417 - FZÚ 2019 RIV NL eng J - Journal Article
Colineau, E. - Boulet, P. - Griveau, J.C. - Eloirdi, R. - Wastin, F. - Shick, Alexander - Caciuffo, R.
Gallium substitution in the transuranium superconductor PuCoGa₅.
Journal of Alloys and Compounds. Roč. 745, May (2018), s. 477-482. ISSN 0925-8388. E-ISSN 1873-4669
R&D Projects: GA ČR GA18-06240S
Institutional support: RVO:68378271
Keywords : actinide alloys and compounds * intermetallics * superconductors * x-ray diffraction * magnetic measurements * electronic properties
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 4.175, year: 2018

We have studied the effects of substituting gallium by aluminum, germanium, tin and indium in PuCoGa5, the actinide-based superconductor with the highest critical temperature. By annealing arc-melted samples, we have been able to synthesize only compounds with 20% substitution by Al and Ge (i.e. PuCoGa4Al and PuCoGa4Ge). Refinements of X-ray powder diffraction patterns for these two compounds indicate an enhanced c/a ratio, whereas magnetic susceptibility measurements reveal a large reduction of the critical temperature T-c compared to PuCoGa5. DFT+ED calculations indicate that the decrease of T-c is accompanied by significant changes in the Fermi surface. Finally, measurements on PuCoGa5 samples made by using Ga-69 and Ga-71 isotopes showed no effect of the atomic mass of gallium on the superconducting critical temperature.
Permanent Link: http://hdl.handle.net/11104/0290792