Ferromagnetic Ni Nanoparticle with Controlled Anisotropy: From Polyhedral to Planar Tetrapods

Liquid phase syntheses mainly yield nanoparticles with compact shapes, such as spheres or cubes. However, controlling not only the size but also shape of magnetic would enable a fine-tuning their intrinsic properties, due to anisotropy induced by long-range dipolar interactions. We report here fairly simple approach based on reduction an amidinate complex in presence mixture long-chains acid and amine ferromagnetic Ni nanoparticles. The formation stable complexes could be promoted situ increasing concentration, thus allowing tuning final particle size. While used soft reducing agent, dihydrogen was essential promote anisotropic shapes. Electron holography combined micromagnetic simulations showed that resulting impose configurations within planar tetrapods. Regarding heating efficiency, which directly scales hysteresis loop area, maxima 100W·g–1 were found for nanoplates nanorods, opening promising perspectives magnetically catalysis.