Co-59 And As-75 Nmr Investigation Of Lightly Doped Ba(Fe1-Xcox)(2)As-2 (X=0.02,0.04)

We investigate the electronic properties of Ba(Fe1-xCox)(2)As-2 (x=0.02,0.04) in the lightly electron-doped regime by Co-59 and As-75 NMR. We demonstrate that Co doping significantly suppresses the magnetic ordering temperature to the SDW state, T-SDW. Furthermore, ordered moments below T-SDW exhibit large distribution. Strong spin fluctuations remain even below T-SDW, persisting all the way down to 4.2 K. We find no signature of additional freezing of spin degrees of freedom unlike the case of the lightly hole-doped stripe phase of the cuprates.