Rod-shaped nanostructures of cobalt oxalate dihydrate were synthesized at room temperature by the microemulsion (reverse micellar) route. These rods are highly uniform in length and can be modified with temperature (from ∼6.5 μm at 50 °C to ∼2.5 μm at 150 °C) while keeping the diameter nearly constant (200-250 nm). Thermal decomposition of these rods in a controlled atmosphere (air and H2) leads to nanoparticles of Co3O4 and Co, respectively, while in a helium atmosphere a mixture of Co and CoO nanoparticles is obtained. Co3O4 nanoparticles (∼35 nm) were slightly agglomerated, while Co nanoparticles were monodispersed and highly uniform (∼25 nm). The oxalate rods and Co3O4 nanoparticles show an antiferromagnetic ordering at 54 and 35 K, respectively.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Surfaces, Coatings and Films
- Colloid and Surface Chemistry