Gallium substitution in the transuranium superconductor PuCoGa5

JOURNAL OF ALLOYS AND COMPOUNDS

卷:745

Article

Colineau, E.¹  Boulet, P.²  Griveau, J. -C.¹  Eloirdi, R.¹  Wastin, F.¹  Shick, A. B.³  Caciuffo, R.¹ 

[1] European Commiss, Directorate Nucl Safety & Secur, Joint Res Ctr, Postfach 2340, D-76125 Karlsruhe, Germany

[2] Univ Lorraine, CNRS, Inst Jean Lamour, UMR 7198, 2 Allee Andre Guinier,BP50840, F-54011 Nancy, France

[3] ASCR, Inst Phys, Na Slovance 2, CZ-18221 Prague, Czech Republic

关键词: Actinide alloys and compounds;    Intermetallics;    Superconductors;    X-ray diffraction;    Magnetic measurements;    Electronic properties;   

DOI  :  10.1016/j.jallcom.2018.02.116

来源: Elsevier

【 摘 要 】

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. (C) 2018 Elsevier B.V. All rights reserved.

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