Disclosed herein are compounds, methods, and tools which comprise tungsten borides and mixed transition metal borides.

Radiofrequency and other electronic devices can be formed from textured hexaferrite materials, such as Z-phase barium cobalt ferrite Ba.sub.3Co.sub.2Fe.sub.24O.sub.41 (Co.sub.2Z) having enhanced resonant frequency. The textured hexaferrite material can be formed by sintering fine grain hexaferrite powder at a lower temperature than conventional firing temperatures to inhibit reduction of iron. The textured hexaferrite material can be used in radiofrequency devices such as circulators or telecommunications systems.

A honeycomb structure according to at least one embodiment of the present invention includes: a honeycomb structure portion having: an outer peripheral wall; and a partition wall arranged inside the outer peripheral wall to define a plurality of cells each extending from a first end surface of the honeycomb structure portion to a second end surface thereof to form a flow path; and a pair of electrode portions arranged on an outer peripheral surface of the outer peripheral wall of the honeycomb structure portion. The electrode portions are each a porous body in which particles of silicon carbide are bound by a binding material, the silicon carbide contains α-type silicon carbide and β-type silicon carbide, and the silicon carbide has a D50 in a volume-based cumulative particle size distribution of 25 μm or less.

A sialon sintered body and a cutting insert each having thermal shock resistance and VB wear resistance. The sialon sintered body and the cutting insert contain β-sialon and 21R-sialon and exhibit an X-ray diffraction peak intensity ratio R[(I.sub.21R/I.sub.A)×100] of 5% or greater and smaller than 30%, wherein I.sub.A represents the sum of the peak intensities of the sialon species, and I.sub.21R represents the peak intensity of 21R-sialon, the ratio being calculated from the peak intensities of the sialon species obtained by using X-ray diffractometry.

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.

A sintered ferrite magnet comprising (a) a ferrite phase having a hexagonal M-type magnetoplumbite structure comprising Ca, an element R which is at least one of rare earth elements and indispensably includes La, an element A which is Ba and/or Sr, Fe, and Co as indispensable elements, the composition of metal elements of Ca, R, A, Fe and Co being represented by the general formula of Ca.sub.1-x-yR.sub.xA.sub.yFe.sub.2n-zCo.sub.z, wherein the atomic ratios (1-x-y), x, y and z of these elements and the molar ratio n meet the relations of 0.3≦(1-x-y)≦0.65, 0.2≦x≦0.65, 0≦y≦0.2, 0.03≦z≦0.65, and 4≦n≦7, and (b) a grain boundary phase indispensably containing Si, the amount of Si being more than 1% by mass and 1.8% or less by mass (calculated as SiO.sub.2) based on the entire sintered ferrite magnet, and its production method.

An oxide ceramic having a principal component formed of a ferrite compound containing at least Sr, Co, and Fe, and zirconium in an amount of 0.05 to 1.0 wt. % on an oxide equivalent basis, and a ceramic electronic component using the oxide ceramic.

A ceramic composite can include a first ceramic phase and a second ceramic phase. The first ceramic phase can include a silicon carbide. The second phase can include a boron carbide. In an embodiment, the silicon carbide in the first ceramic phase can have a grain size in a range of 0.8 to 200 microns. The first phase, the second phase, or both can further include a carbon. In another embodiment, at least one of the first ceramic phase and the second ceramic phase can have a median minimum width of at least 5 microns.

Radiofrequency and other electronic devices can be formed from textured hexaferrite materials, such as Z-phase barium cobalt ferrite Ba.sub.3Co.sub.2Fe.sub.24O.sub.41 (Co.sub.2Z) having enhanced resonant frequency. The textured hexaferrite material can be formed by sintering fine grain hexaferrite powder at a lower temperature than conventional firing temperatures to inhibit reduction of iron. The textured hexaferrite material can be used in radiofrequency devices such as circulators or telecommunications systems.

A manganese oxide contains M1, optionally M2, Mn and O. M1 is selected from the group consisting of In, Sc, Y, Dy, Ho, Er, Tm, Yb and Lu. M2 is different from M1, and M2 is selected from the group consisting of Bi, In, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. These ceramic materials are hexagonal in structure, and provide superior materials for gas separation and oxygen storage.