Synthesis and Characterization of Superparamagnetic Ni−Pt Nanoalloy

Abstract

A room-temperature wet chemical method of synthesis for sphere- and rod-shaped magnetic “solid solution” type Ni−Pt nanoparticles in cetyltrimethylammonium bromide (CTAB) micelle is reported. The particles have been found to be moderately monodispersed without adopting any further size-selection procedure. The composition of the alloy becomes tunable through adjustment of the ratio of the reactants. The temperature-dependent magnetic property, size distribution, and percentage composition of the alloyed structures are characterized by SQUID magnetometer, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and electron dispersive X-ray (EDX) analyses. The preferential evolution of nanorods over spherical particles in higher surfactant concentrations and the coalescence of the magnetic particles have been examined.