The Research Of Hydrothermal Synthesis Of Hexagonal Ferrites

Due to the rapid development of the applications of integrated ferroelectric and spintronics,multiferroic materials has been widely studied.Z-type hexagonal ferrite is a multiferroic materials.It is one of the few materials that show the magnetoelectric effect at room temperature. Single-phase Z-type hexagonal ferrite to demonstrate magnetoelectric effect is associated to the orientation degree of ferrite.Using traditional solid phase method and other methods are difficult to obtain good orientation degree.Under this situation, this thesis adopted the hydrothermal synthesis method preparation of lamellate hexagonal ferrite.Research work have been done to prepare the single-phase Z-type hexagonal ferrite.Lamellate Z-type hexagonal ferrites were synthesized by a hydrothermal method. The Z-type hexagonal ferrites have been studied in term of doping modification and different preparation process.The contents of the thesis are organized as follows.1.The effects of atomic ratio of Sr/Fe on the phase composition,performance parameters of the Z-type hexagonal ferrites were investigated. The best atomic ratio of Sr/Fe is identified.2.The influence of hydrothermal temperature on the phase structure, performance parameters of the Z-type type hexagonal ferrite were investigated and determined the optimal hydrothermal reaction temperature.It was found to improve the hydrothermal temperature conducive ferrite formation.3.The influence of duration of hydrothermal treatment on the phase structure and performance parameters of Z-type hexagonal ferrite were investigated. Experiments show that the Z-type hexagonal ferrites can be obtained between 40 hours to 46 hours.The optimal time was 42 hours.4.The effect of sintering temperature on Z-type hexagonal ferrites were investigated.The experiments show that when the sintering temperature increased, the generation of Z-type hexagonal ferrite was promoted,and material permeability and permittivity were improved.5. The effect of SiO₂ doping on Z-type hexagonal ferrites were investigated. As the SiO₂ doping amount increase,the permeability and permittivity of material is subsequently decreased.