There is provided a ferrite sintered magnet having a high residual magnetic flux density.

A ferrite sintered magnet 2 includes a plurality of main phase particles 5 including ferrite having a hexagonal structure, the number of core-shell structured particles 5A having a core 7 and a shell 9 covering the core 7, among the main phase particles 5, is smaller than the number of the main phase particles 5 other than the core-shell structured particles 5A.

Provided is a ferrite sintered magnet including a main phase formed of ferrite having a hexagonal magnetoplumbite type crystalline structure, in which the main phase contains Fe and Co, and the ferrite sintered magnet contains CaB.sub.2O.sub.4. CaB.sub.2O.sub.4 is contained in a heterophase that is a crystalline phase different from the main phase, and an area ratio of CaB.sub.2O.sub.4 to the entire cross-sectional surface of a sintered magnet, is less than or equal to 2%.

Disclosed are a zirconia-based antibacterial denture material and a preparation method thereof. The zirconia-based antibacterial denture material includes components with the following mass parts: 75 to 80 parts of zirconium oxide, 2 to 5 parts of nanosized silver oxide, 3 to 5 parts of nanosized zinc oxide, 1 to 3 parts of nanosized lanthanum oxide, 1 to 3 parts of nanosized yttrium oxide, 1 to 2 parts of cerium oxide, and 1 to 2 parts of size control agent. The zirconia-based antibacterial denture material has good antibacterial effect and high strength.

The present invention provides a ferrite magnetic material that is inexpensive by reducing the contents of La and Co and capable of providing a remarkably high maximum energy product ((BH).sub.max) as compared with the conventional ferrite magnetic materials by inducing a high saturation magnetization and a high anisotropic magnetic field.

Molded devices are made by a molding method comprising use of magnetic fields to place magnetic particles into optimal configurations. The optimal configurations are set in place by the curing of a continuous solid-forming mixture that surrounds the particles. An example system uses urethane monomers to set iron powder mixtures into an inner and outer core of an electromagnetic coil. In addition to attractive forces to concentrate ferromagnetic particles, repulsive forces may be used to concentrate diamagnetic particles of aluminum or copper.

This ferrite magnet has a ferrite phase having a magnetoplumbite structure, and an orthoferrite phase, and is characterized in that the composition ratios of the total of each metal element A, R, Fe and Me is represented by expression (1) A.sub.1-xR.sub.x(Fe.sub.12-yMe.sub.y).sub.z, (in expression (1), A is at least one element selected from Sr, Ba, Ca and Pb; R is at least one element selected from the rare-earth elements (including Y) and Bi, and includes at least La, and Me is Co, or Co and Zn) and in that the content (m) of the orthoferrite phase is 0<m<28.0 in mol %. The invention makes it possible to achieve a ferrite magnet with increased Br.

A production process for a crystal oriented ceramics includes: a first step of preparing composite particles formed of particles having magnetic anisotropy having magnetic susceptibility anisotropy and seed particles having magnetic susceptibility anisotropy less than or equal to 1/10 of the magnetic susceptibility anisotropy of the particles having magnetic anisotropy and are formed of an inorganic compound having an anisotropic shape in which a crystal axis intended to be corresponds to a minor axis or a major axis; a second step of adding raw material powder including the composite particles to a solvent to prepare a slurry a third step of preparing a green compact by disposing the slurry in a static magnetic field of 0.1 tesla and drying the slurry in a state in which crystal axes of the seed particles in a major axis direction are in one direction; and a fourth step of sintering the green compact.

This ferrite magnet has a magnetoplumbite structure and is characterized in that, when representing the composition ratios of the total of each metal element A, R, Fe and Me with expression (1) A.sub.1-xR.sub.x(Fe.sub.12-yMe.sub.y).sub.z, the Fe.sup.2+ content (m) in the ferrite magnet is greater than 0.1 mass % and less than 5.4 mass % (in expression (1), A is at least one element selected from Sr, Ba, Ca and Pb; R is at least one element selected from the rare-earth elements (including Y) and Bi, and includes at least La, and Me is Co, or Co and Zn). The invention makes it possible to achieve a ferrite magnet with increased Br.

A ferrite sintered magnet includes a composition expressed by a formula (1) of Ca.sub.1-w-xLa.sub.wA.sub.xFe.sub.zCo.sub.mMn.sub.aO.sub.19. In the formula (1), w, x, z, m, and a satisfy a formula (2) of 0.21w0.62, a formula (3) of 0.02x0.46, a formula (4) of 7.43z11.03, a formula (5) of 0.18m0.41, and a formula (6) of 0.046a0.188. In the formula (1), A is at least one kind of element selected from a group consisting of Sr and Ba.

A piezoelectric ceramic base body that has a polyhedral shape having shape anisotropy, such as a rectangular parallelepiped shape, and which has opposed faces on which external electrodes are formed. The opposed faces have first sides and second sides. Between the first side and the second side of one of the opposed faces, a width dimension of the surface in a direction orthogonal to the first side and the second side is larger than a length dimension of each of the first and the second sides. The crystal axis is {100} oriented in a direction parallel to the first and the second sides, and a degree of orientation by a Lotgering method is 0.4 or more.