Thin films consisting of granular dispersions of cobalt nano-particles in a hydrocarbon matrix are fabricated by simultaneous sputtering of cobalt and plasma induced polymerization of hydrocarbon monomers. It is confirmed that cobalt nano-particles with a hexagonal close-packed (hcp) structure are uniformly distributed throughout the amorphous hydrocarbon matrix. In-plane magnetic hysteresis loops obtained by MOKE (Magneto-Optic Kerr Effect) magnetometry measurements show significant differences between granular cobalt crystallites dispersed throughout the polymeric film matrix and cobalt crystallites in a continuous polycrystalline pure cobalt film due to the mechanism of domain boundary pinning. For the first time, the domain structures and wall motion in a cobalt/polymer system are captured in real time by Lorentz microscopy.
Bibliographical noteFunding Information:
One of the autlhors (J. H.) wishes to thank A. Marshall, K. Sin and H. Lee for discussions and helpful advice. This work is supported in part by the Center on Polymer Interfaces and Macromolecular Assemblies, and by Center for Materials Research at Stanford University.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering