  We use NMR techniques to investigate the magnetic properties of BaCo2As2
single crystals, the non-superconducting end member of the Co-substituted
iron-pnictide high Tc superconductor Ba(Fe1-xCox)2As2 with x = 1. We present
75As NMR evidence for enhancement of low frequency spin fluctuations below ~
100 K. This enhancement is accompanied by that of static uniform spin
susceptibility at the wave vector q = 0, suggesting that the primary channel of
the spin correlations is ferromagnetic rather than antiferromagnetic.
Comparison between the NMR Knight shift 75K and bulk susceptibility chi(bulk)
data uncovers the presence of two separate components of spin susceptibility
with distinct temperature dependences, presumably because multiple electronic
bands crossing the Fermi energy play different roles in the electronic
properties of BaCo2As2.
