Study on the magnetic properties of metal-oxide quantum dots embedded in a polyimide layer

A mono-layer of quantum dots (QDs) was fabricated in polyimide matrix by chemical reaction between polyamic acid and metal thin film. This method has advantages of simple fabrication steps and diversity of material choice. Fe2O3 and ZnO QDs were embedded in a polyimide matrix, and their electrical charging effects were measured. From the magnetization analysis, the Fe2O3 particles not to have much of a gamma-Fe2O3 crystal structure. From the magnetic force microscope (MFM) image of a single particle under a static magnetic filed, this fabrication method is thought to be able to produce only low-density magnetic QDs and the almost magnetic property the non-reacted Fe metal. Though only low-density magnetic particles are formed, the MFM image showed single gamma-Fe2O3.