  The spin Hall effect and its inverse are important spin-charge conversion
mechanisms. The direct spin Hall effect induces a surface spin accumulation
from a transverse charge current due to spin orbit coupling even in
non-magnetic conductors. However, most detection schemes involve additional
interfaces, leading to large scattering in reported data. Here we perform
interface free x-ray spectroscopy measurements at the Cu L_{3,2} absorption
edges of highly Bi-doped Cu (Cu_{95}Bi_{5}). The detected X-ray magnetic
circular dichroism (XMCD) signal corresponds to an induced magnetic moment of
(2.7 +/- 0.5) x 10-12 {\mu}_{B} A^{-1} cm^{2} per Cu atom averaged over the
probing depth, which is of the same order as for Pt measured by magneto-optics.
The results highlight the importance of interface free measurements to assess
material parameters and the potential of CuBi for spin-charge conversion
applications.
