Cobalt (Co) layers with a thickness of up to 50 nm have been electrodeposited under the influence of magnetic fields up to 10 T aligned perpendicular or parallel to the electrode surface. The crystallographic orientation and the phase composition of these layers have been investigated by X-ray diffraction and transmission electron microscopy. The layers consist mainly of the face centered cubic phase with a < 111 > orientation perpendicular to the electrode surface which results from the low surface free energy of these planes. An influence of magnetic fields on the crystallographic orientation has not been observed. It was found that magnetic fields affect the phase composition which results predominantly from the influence of the magnetic fields on the electrochemistry. The nucleation has been studied by in-situ scanning tunneling microscopy. (c) 2006 Elsevier B.V. All rights reserved.