We reported a single step process for the synthesis of Ni having wire, sponge and flower type microstructures that are obtained via a microwave-assisted decomposition of Ni-TEA (triethanolamine) complex precursor with and without amino acid. The products formed at different stages of the growth process were characterized using scanning electron microscope (SEM), transmission electron microscope (TEM) and magnetometer. Morphological modification enhanced the coercivity from 40 Oe for the Ni-wire to 120 Oe for the Ni-flower with exchange bias effect, which mechanistically arises due to the presence of NiO phase. © 2008 American Institute of Physics.