| Ring-opening metathesis polymerization (ROMP) of norbornene and its derivatives has proven to be a very effective way of synthesizing block copolymers of narrow polydispersity. These block copolymers can be used effectively as a template to form nanoclusters of inorganic materials. Nanocrystalline oxide spinels are of interest both for fundamental studies in magnetism and technological applications. Spinel cobalt ferrite, CoFe 2O4 is a well known hard magnetic material with very high cubic magnetocrystalline anisotropy, high coercitivity and moderate saturation magnetization. These properties make it a promising material for high density magnetic recording applications.; In this thesis, the synthesis of uniformly distributed CoFe 2O4 and cobalt oxide nanoparticles within microphase separated domains of diblock copolymers in a controlled manner will be discussed. Transmission electron microscopy, superconducting quantum interference device (SQUID) magnetometry and x-ray powder diffraction were used to investigate the morphology and magnetic properties of the nanocomposites. Polymer templated CoFe2O 4 and cobalt oxide nanocomposites synthesized for the study have spherical morphology and metal oxide nanoclusters are uniformly distributed within the polymer matrix. By varying the block ratio of the block copolymers we were able to control the size and the magnetic properties of CoFe 2O4 nanoparticles. The novel room temperature templating strategy used for the synthesis of these magnetic nanocomposites requiring no thermal cycling steps, which makes it particularly attractive for integration into the fabrication of novel magnetic devices. |
