Morphological, physicochemical and magnetic characterization of electrodeposited Mn-Bi and Mn-Bi/Bi thin films on Cu Substrate

Mn-Bi thin films were electroplated on Cu (111) substrates in an acidic chloride bath. In order to determine the deposition potential of each element, cyclic voltammetry using a rotating disk electrode was performed. Two types of thin films were obtained using two deposition mode: the first one called thin Mn-Bi layers by using a single applied potential and the second one called Mn-Bi/Bi bilayers by using a double pulse potential. Annealing treatments at 300 °C for 1 hour under vacuum condition were carried out in order to cause an interdiffusion between manganese and bismuth. The morphological and crystalline structure of the various deposits was investigated by scanning electron microscopy with field effect (SEM-FEG) and by X-ray diffraction analysis (XRD). Magnetic characterizations were also made using a superconducting quantum interference device (SQUID) magnetometer.The morphological and the structural properties of the thin layers and the bilayers are completely different, indicating that the growth process changes according to the plating mode. After annealing a mixed MnBiCu phase with a coercivity of 300 Oe and 400 Oe was observed on the thin layers and the bilayers respectively.