Effect of nucleating agents on synthesis of CoNi alloy particles via polyol process

CoNi alloy particles were synthesized via the polyol process using nucleating agents such as copper (II) acetylacetonate and K2PtCl4. The phase, morphology, mean size, and magnetic properties were evaluated using X-ray diffractometry, field emission scanning electron microscopy, and a vibrating samples magnetometer. At [Cu]/[Co+Ni]=1×10−6, the size of the CoNi alloy particles was approximately 320 nm. When the nucleation molar ratio [Pt]/[Co+Ni] was 8×10−5, the size decreased to 95 nm. This indicates that K2PtCl4 is a more effective nucleating agent for controlling the size of CoNi nanoparticles at the tens to hundreds of nanometers scale. The magnetic properties showed that the CoNi alloy particles are typical soft magnetic materials. The coercivity of CoNi alloy particles prepared by using K2PtCl4 as a nucleating agent was higher than of particles prepared by using copper (II) acetylacetonate.