H. Z. Chen

Well-defined 1-D ZnO and ZnO:Cu semiconductor nanostructures have been fabricated by a low temperature solution process. Cu (0.073 nm) is chosen as a dopant due to the similar ionic radius with Zn (0.074 nm). The radius of ZnO:Cu nanorods observed by FE-SEM is lager than that of pure ZnO which indicates the growth rate of the nanorods can be obviously enhanced by the light doping of Cu. The XRD patterns of both compositions with single diffraction peak (002) show the same wurtzite hexagonal structure. Photoluminescence spectra show a red-shift of the UV emission peak position and a decrease of the luminescence intensity in green-yellow region. From the room temperature hysteresis loop, ferromagnetism is observed and the saturation magnetization decreases with the increase of the Cu concentration for ZnO:Cu nanorods.

Nanoparticle films of ferrite were synthesized using the chemical co-precipitation technique. It was shown that densely packed ferrite films with a thickness of 7 μ m can be deposited from fine particles with an average particle size of 10–20 nm on the Si substrate. The particle size, composition, and magnetic properties of the films are affected by the pH value of the reactive solutions. For samples with a lower pH value, the particles are small and agglomerate together. Conversely, for samples with a higher pH value, the particles are large and uniformly distributed. Samples fabricated with a higher pH value show large values of magnetization and lower values of coercive force. The result of larger magnetization relates to larger particle size and a more uniform distribution for samples fabricated with a higher pH value.