Characterization of electrolytic composite layers containing cobalt and nickel oxide in amorphous alloy matrix Ni-P
Magdalena Popczyk, Antoni Budnik Uniwersytet Śląski, Instytut Nauki o Materiałach, ul. Bankowa 12, 40-007 Katowice
Annals 4 No. 9, 2004 pages 104-108
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abstract Electrodeposited Ni-P+NiO+Co and Ni-Co-P+NiO composite layers were obtained in the galvanostatic conditions (j = = 0.200 A cm−2), at the temperature of 298 K. For comparison the Ni-P layer was also obtained and investigated in the same manner. The phase composition of the layers was performed using a Philips diffractometer and the chemical composition - by the atomic absorption method using a Perkin-Elmer spectrometer. Stereoscopic and scanning microscope, X-ray microanalyser and Form Talysurf - type profilograph were used for surface characterization of the layers. All obtained layers, show good adhesion to the substrate. In contradistinction from smooth Ni-P layer, Ni-P+NiO+Co and Ni-Co-P+NiO composite layers to characterize of a mat and rough surface, with visible grains of embedded powder. The surfaces of Ni-P+NiO+Co and Ni-Co-P+NiO composite layers are more developed in comparision to Ni-P layer (Figs 1, 2). Linear analysis of distribution of nickel and cobalt in the Ni-P+NiO+Co and Ni-Co-P+NiO composite layers, show in the one case local differentiation of chemical composition of these elements and in the other case as far as uniformly presence of these elements in the layer (Fig. 3). XRD investigations for Ni-P+NiO+Co layer show presence of amorphous structure of Ni-P with particles of nickel oxide and cobalt embedded to the matrix (Fig. 4b). However, XRD investigations for Ni-Co-P+NiO layer show of two-phase structure. Sharp reflexes on the diffraction pattern prove about presence of crystalline nickel oxide in the amorphous Ni-Co-P matrix (Fig. 4c). Introduction of cobalt through electrolytic of codeposition with ionic form and powder of nickel oxide into electrolytic Ni-P matrix, causes of obtaining layer about very developed, rough surface (Ni-Co-P+NiO). This obtained composite layer maybe useful as electrode material in electrochemistry, particularly in the process of hydrogen electroevolution. Key words: amorphous nickel matrix, cobalt, nickel oxide, composite layers