  We have used a MHz lock-in x-ray spectro-microscopy technique to directly
detect changes of magnetic moments in Cu due to spin injection from an adjacent
Co layer. The elemental and chemical specificity of x-rays allows us to
distinguish two spin current induced effects. We detect the creation of
transient magnetic moments of $3\times 10^{-5}$ $\mu_\mathrm{B}$ on Cu atoms
within the bulk of the 28 nm thick Cu film due to spin-accumulation. The moment
value is compared to predictions by Mott's two current model. We also observe
that the hybridization induced existing magnetic moments on Cu interface atoms
are transiently increased by about 10% or $4\times 10^{-3}$ $\mu_\mathrm{B}$.
This reveals the dominance of spin-torque alignment over Joule heat induced
disorder of the interfacial Cu moments during current flow.
