Low Temperature Sintering Of Hexagonal M-type Barium Ferrite Materials And Magnetic Properties

The work of this paper surround millimeter-wave gyromagnetic ferrite component's hex-ferrite to expand, Using the ceramics and adjusting the adulteration and technology, M-type Ba ferrite material for microwave ferrite component was prepared in order to fit the LTCF(low temperature co-fire ferrite) technology. The research include: the relation of material structure and performance; the relation of microstructures and technics parameter; the relation of high frequency magnetic properties and compositions,material structure and technology; the mechanism of low temperature sinter. Through fine milling and adding dopants, one kind of applicable low temperature co-fired M-type Ba ferrite material was prepared in order to fit the LTCF technology.In the part of experiments investigations, one kind of applicable low temperature co-fired M-type Ba ferrite material was prepared by the oxide method (solid-phase reaction). At first the basic principle of the compositions was defined, In this foundation, the relation of material structure and performance;the relation of microstructures and technics parameter; the relation of high frequency magnetic properties and compositions,material structure and technology was studied, Effect of adding Bi2O3 on the electromagnetic properties of Ba ferrite was investigated, it showed that adding this dopants can reduce the sintering temperature of Ba ferrite material evidently. The improvement on the electromagnetic properties of Ba ferrite by controling different ion substitute(such as ZnTi,CoTi) were studied also. Finally, the high performance Ba ferrite material was prepared on the condition of first milling is 6 hours, calcining at 1100℃, adding 3.0wt%Bi₂O₃ or 0.75wt% V₂O₅, second milling for 9h, sintering at 900℃. Through adding the dopant, low temperature of M-type ferrite was obtained. Because M-type Ba ferrite has high anisotropy inner field, the decrease of the ferrite sintering temperature makes the slice millimeter wave component through LTCF technology to become possible.