Controlling the size and morphology of anisotropic nanostructures of nickel borate using microemulsions and their magnetic properties

Anisotropic nanostructures of nickel borate with controlled size and morphology have been synthesized by a precursor-mediated route. The nickel boron precursor has been synthesized using microemulsions using Tergitol as a surfactant. Microemulsions with various co-surfactants (1-butanol, 1-hexanol and 1-octanol) have been used to obtain uniform nanorods (dia 3-5 nm, length 25 nm) and nanospindles (dia 30 nm, length 400 nm). A higher chain length of the co-surfactant (octanol) leads to more uniform rods rather than spindles (butanol). These nanorods show antiferromagnetic behavior with the Neel temperature ranging from 44 to 47 K. Though there is no marked variation in Neel temperature, the magnetic moment increases drastically with the anisotropy of nanorods (thinner rods). (C) 2011 Elsevier Inc. All rights reserved.