A method for improving the Bs of an MnZn power ferrite material by moving the valley point includes the following steps: 1) mixing Fe.sub.2O.sub.3, MnO and ZnO, and performing primary sanding; 2) adding glue, performing spraying and granulating, and then performing pre-sintering to obtain a pre-sintered material; 3) adding additives to the pre-sintered material, and performing secondary sanding; and 4) adding glue to the secondary sanded material, performing spraying and granulating, pressing into a standard ring, and then performing sintering. The method controls and moves the valley point, reduces loss and improves the Bs of a material by controlling the Fe.sub.2O.sub.3 content and the Co.sub.2O.sub.3 content, and the method is relatively simple and suitable for industrialization.

A multilayer coil component that includes a multilayer body in which a plurality of insulating layers are stacked in a stacking direction and a coil inside the multilayer body, and outer electrodes that are on surfaces of the multilayer body and are electrically connected to the coil. The insulating layers include a spinel-structure ferrite phase and a ZnFe(BO.sub.3)O-type crystalline phase.

A multilayer coil component includes a multilayer body in which a plurality of insulating layers are stacked in a stacking direction and a coil inside, and outer electrodes on surfaces of the multilayer body and electrically connected to the coil. The insulating layers have a magnetic phase having spinel structure containing at least Fe, Ni, Zn, and Cu and a non-magnetic phase containing at least Si. When grain sizes D50 and D90 of crystal grains constituting the magnetic phase are respectively defined as equivalent-area circle diameters of 50% and 90% on a cumulative sum basis in a cumulative distribution of equivalent-area circle diameters of the crystal grains, the grain size D50 is from 50 nm to 750 nm, and the grain size D90 is from 200 nm to 1500 nm.

A method of rapid treatment of heavy metal sludge and preparation of ferrite magnets comprises following steps of: providing a sludge, the sludge at least having zinc metal and ferrous metal; adding an iron-containing substance to the sludge; pickling the sludge and the iron-containing substance with sulfuric acid to obtain a pickling solution with zinc ions and iron ions; neutralizing the pickling solution with sodium hydroxide to form hydroxide precipitates; and airing and heating the neutralized pickling solution by an ultrasonic-microwave method so that the hydroxide precipitates undergoing a ferrite magnet reaction, thereby obtaining ferrite magnets with a spathic structure.

The present invention relates to a process for preparing a rodlike magnetic ferroferric oxide (Fe.sub.3O.sub.4) material and use thereof. The preparation includes the following steps: step 1: magnetic Fe3O4 nanoparticle preparation; and step 2: self-assembly of magnetic Fe3O4@SiO2 nanoparticles into a rodlike magnetic material. When in use, the rodlike magnetic Fe.sub.3O.sub.4 material prepared by the process according to claim 1 is used in micro- and nano-motors, which can implement rotation and deflection in an external magnetic field. The present invention provides a process for preparing a rodlike magnetic Fe.sub.3O.sub.4 material. The rodlike magnetic ferroferric oxide material prepared by the process is suitable for mass production on an industrial scale, featuring identifiable direction of the magnetic moment, strong magnetism, good magnetic response, simple process, and low cost.

An inductor core includes a pillar shaped magnetic main body comprising a magnetic material including pores. The magnetic main body includes: an inclined portion including an inclined surface that constitutes an outer circumferential surface of a truncated cone having an increasing outer diameter; and a straight body portion that is coaxial with the inclined portion and includes an outer peripheral surface that constitutes an outer circumferential surface of a cylindrical column body, the straight body portion being connected to the inclined portion. A difference between an average value of inter-centroid distances of the pores at the straight body portion and an average diameter of the pores at the straight body portion is greater than a difference between an average value of inter-centroid distances of the pores at the inclined portion and an average diameter of the pores at the inclined portion.

A radio wave absorber includes hexagonal ferrite particles and a holding material-filled with the hexagonal ferrite particles. The hexagonal ferrite particles include first particles and second particles that are larger than the first particles in particle size.

Provided are a ferrite powder that suppresses decreases in saturation magnetization and decreases in filler filling ratio and also suppresses inhibition of resin curing, and a method for producing the same. A ferrite powder composed of spherical ferrite particles, wherein the ferrite powder contains iron (Fe) 54.0-70.0 mass % and manganese (Mn) 3.5-18.5 mass %, has an average volume particle size of 2.0-20.0 μm, and has a carbon content of 0.100 mass % or lower.

An inductor core includes a magnetic main body having a pillar shape and comprised of a magnetic material. The magnetic main body includes an inclined portion including an inclined surface that constitutes an outer circumferential surface of a truncated cone having an outer diameter increasing from one end toward the other end; and a straight body portion that is coaxial with the inclined portion and includes an outer peripheral surface that constitutes an outer circumferential surface of a cylindrical column body extending from the other end toward the one end, the straight body portion being connected to the inclined portion. An arithmetic mean roughness Ra of an outer peripheral surface of the straight body portion located at or around the other end is smaller than an arithmetic mean roughness Ra of an outer peripheral surface of the straight body portion that is disposed at or around the inclined portion.

In an aspect, a Co.sub.2Z-type ferrite comprises oxides of at least Me, Co, Mo, Li, and Fe; wherein Me is at least one of Ba or Sr. In another aspect, the Co.sub.2Z-type ferrite comprises a Z-type hexaferrite an amount of lithium molybdate. In another aspect, the Co.sub.2Z-type ferrite has a formula Li.sub.2MoO.sub.4.Ba.sub.xSr.sub.3-xCo.sub.2+y−zMe′.sub.yMe″.sub.zFe.sub.24-2y-mO.sub.41, wherein Me′ is at least one of Ti, Mo, Ru, Ir, Zr, or Sn; Me″ is at least one of Zn, Mn, or Mg; x is 0 to 3; y is 0 to 1.8; z is 0 to 1.8; and m is −4 to 4. In yet another aspect, a method of making a Co.sub.2Z-type ferrite comprises milling an initial Co.sub.2Z-type ferrite and Li.sub.2MoO.sub.4 to form a mixed ferrite; and calcining the mixed ferrite to form the Co.sub.2Z-type ferrite.