Magnetic ferrite powder, magnetic ferrite sinter, layered ferrite part, and process for producing layered ferrite part
AssigneeTDK Corporation
InventorsMasami Endo, Atsuyuki Nakano
Life of this patent
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Abstract
Provided is magnetic ferrite powder in which a peak intensity ratio of Z phase (M3Me2Fe24O41: M=one or more kinds of alkaline-earth metal, Me=one or more kinds from Co, Ni, Mn, Zn, Mg and Cu) of hexagonal ferrite is 30% or higher in X-ray diffraction and a peak value of a grain size distribution is in a range from 0.1 μm to 3 μm.
Claims17
Magnetic ferrite powder,
- wherein a peak intensity ratio of Z phase (M3Me2Fe24O41:
- M=one or more kinds of alkaline-earth metal, Me=one or more kinds selected from Co, Ni, Mn, Zn, Mg and Cu) of hexagonal ferrite is 30% or higher in X-ray diffraction, and
- a peak value of grain size distribution is within a range from 0.1 μm to 3 μm.
Magnetic ferrite powder,
- wherein Z phase (where M=Ba, Me=one or more kinds selected from Co, Ni, Mn, Zn, Mg and Cu) indicated as M3Me2Fe24O41 forms a main phase, and
- a powder specific surface area is from 5 m2/g to 30 m2/g.
A sintered body of magnetic ferrite,
- wherein a Z phase (M=Ba, Me=one or more kinds selected from Co, Ni, Mn, Zn, Mg and Cu) indicated as M3Me2Fe24O41 forms a main phase,
- CuO and Bi2O3 are included by 0.5 wt % to 20 wt % in total,
- CuO mainly exists within grains, and
- Bi2O3 mainly exists at grain boundaries.
Sintered body of magnetic ferrite,
- wherein Z phase (where M=Ba, Me=one or more kinds selected from Co, Ni, Mn, Zn, Mg and Cu) indicated as M3Me2Fe24O41 forms a main phase, and
- Bi2O3 based glass and CuO are added by 1 wt % to 20 wt % in total.
A multilayer ferrite chip component in which a magnetic ferrite layer and an internal electrode are stacked alternately, the multilayer ferrite chip component comprising an external electrode electrically connected with said internal electrode,
- wherein said magnetic ferrite layer has Z phase (M3Me2Fe24O41:
- M=one or more kinds of alkaline-earth metal, Me=one or more kinds selected from Co, Ni, Mn, Zn, Mg and Cu) of hexagonal ferrite as a main phase in X-ray diffraction, the magnetic ferrite layer being constituted of sintered body of magnetic ferrite having a mean grain size of 1 to 5 μm, and
- said internal electrode is constituted of any one of Ag and an Ag alloy.
A manufacturing method of a multilayer ferrite chip component in which a magnetic ferrite layer and an internal electrode are stacked, comprising the steps of:
- mixing raw material powder of magnetic ferrite;
- calcining the mixed raw material powder in a temperature range of 1200° C. or higher;
- milling the obtained calcined body so as to make a peak value of grain size distribution fall into a range from 0.1 to 3 μm;
- obtaining a sheet or paste for forming a magnetic layer by using the obtained milled powder;
- obtaining a laminated green body by alternately stacking material for the internal electrode and any one of said sheet and said paste;
- and
- sintering said laminated green body at a temperature lower than 960° C.,
- wherein said magnetic ferrite layer consists of sintered body of magnetic ferrite having a peak intensity ratio of Z phase (M3Me2Fe24O41:
- M=one or more kinds of alkaline-earth metal, Me=one or more kinds selected from Co, Ni, Mn, Zn, Mg and Cu) of hexagonal ferrite at 30% or greater in X-ray diffraction.
Dependencies are inferred from the claim text.