Preparation And Properties Of ZnO-based Diluted Magnetic Semiconductors

Diluted magnetic semiconductors(DMSs)play an indispensable role in the development of novel spintronic devices due to their own unique physicochemical properties combined with excellent semiconductor properties and magnetism.Among them,ZnO-based DMSs have become the subject of scientific research because of their excellent physical and chemical properties.In this paper,coprecipitation method was used to prepare complex precursors containing transition metals(Fe,Co,Ni,Cu)and lanthanide metal(Tb).A series of metal ion-doped ZnO diluted magnetic semiconductor were prepared by different treatments of the precursor and calcination.The morphology,optical properties and magnetic properties of the products were characterized and studied by IR,UV-Vis,X-ray diffraction,SEM and magnetic measurements.The morphological structure of the samples shows that we successfully prepared homogeneous phase dilute magnetic semiconductors doped with Ni,Fe,Co and Cu.The max solubility of Fe and Co in ZnO reaches 5%.Ni and Co doped ZnO obtained by calcination under the package of vaseline showed the film-like structure.Ni and Co doped samples obtained by direct calcination showed the microstructure of the microspheres,and exhibited some regularity with the doping amount.Tb-doped ZnO samples showed rod accumulation and lamellar accumulation.The optical properties of ZnO samples after doping showed the maximum absorption peak near 370 nm in UV region,which is attributed to the intrinsic absorption of ZnO.In addition to Ni,the optical band gap value of samples showed a trend of regular decrease along with the increase of transition metal doping,and the red edge shift of the absorption band appears obviously.It is demonstrated that the transition metal is successfully doped into the crystal lattice and has an impact on the optical properties of ZnO.The magnetic performance results indicated that the transition metal doped ZnO products with the exception of some Cu-doped samples,have room temperature ferromagnetism.The magnetic properties of Fe and Co doped ZnO products increased with the increase of doping concentration and the magnetic properties of Ni-doped ZnO prepared by the protection of vaseline decreased with the increase of doping concentration.