Coexistent superconductivity and magnetism in Th-dopedCeCu2Si2

Antiferromagnetic order is found in ${\mathrm{Ce}}_{1\mathrm{-}\mathit{x}}$ ${\mathrm{Th}}_{\mathit{x}}$ ${\mathrm{Cu}}_2$ ${\mathrm{Si}}_2$ for 0.1≤x≤0.5, which becomes ferromagnetic in nature for x=0.9. Previous work, which found that superconductivity remains present in Th-doped ${\mathrm{CeCu}}_2$ ${\mathrm{Si}}_2$ up to at least x=0.12, and perhaps as far as x=0.2, is expanded upon to find that superconductivity remains up to at least x=0.25, with ${\mathit{T}}_{\mathit{c}}^{\mathrm{onset}}$=0.25 K. We report the coexistence of a significant bulk ordered moment (∼1/4 of that of a fully ordered spin-1/2 system) coexisting with superconductivity in a heavy-fermion system.