Synthesis and characterization of sub-micron size Co-Ni alloys using malonate as precursor

Sub-micron size (0.2-0.6 mum) particles of Co1-xNix (0 less than or equal to x less than or equal to 1) alloys have been synthesized by the polyol method using Co-Ni malonates as precursors but without using any protective agents such as PVP or any other surfactants. The synthesized alloys are found to be homogeneous. EDX analysis of the alloys showed particle-to-particle uniformity in composition. SEM showed largely non-agglomerated, almost spherical particles, with a fairly narrow size distribution. In the first reported effort of its kind, WAXS analysis was carried out to estimate the amounts of HCP and FCC phases present in pure Co and Co0.8Ni0.2. Coercivity, saturation magnetization and remanent magnetization at room temperature for all the compositions are reported. These results agree well with the composition of the alloys. (C) 2002 Elsevier Science Ltd. All rights reserved.