Quasi-epitaxial growth of Ni nanoshells on Au nanorods

Magnetic nickel shells can be grown on gold nanorods with platinum tips by reduction of Ni2+, with hydrazine in aqueous cetyl-trimethylammonium bromide (CTAB) solution, using Pt tips as catalysts. The plasmon absorption of the starting gold nanorods can be totally quenched by the metallic layer of nickel, while the magnetic character of these anisotropic, hybrid nanocrystals is demonstrated through alignment under an external magnetic field. Quasi-epitaxial growth is demonstrated by HRTEM and electron diffraction (see figure).