Comparative studies of magnetic properties of Co films on annealed and unannealed rubrene/Si(1Â 0Â 0)

- For annealed rubrene/Si(1 0 0) films, rubrene molecules nucleate to form clusters and pinholes develop.
- For Co/rubrene/Si(1 0 0) films, separated Co clusters are found.
- For Co/annealed rubrene/Si(1 0 0) films, the coercive force is enhanced.
- Co islands in triangular shapes play an important role on the enhancement of the squareness of magnetization curve.