A ferrite sintered magnet comprising an M type Sr ferrite having a hexagonal structure as a main phase, wherein the ferrite sintered magnet comprises La and Co, a content of B is 0.005 to 0.9% by mass in terms of B.sub.2O.sub.3, a content of Zn is 0.01 to 1.2% by mass in terms of ZnO, and the ferrite sintered magnet satisfies [La]/[Zn]0.79 and [Co]/[Zn]0.67 when an atomic concentration of La is represented by [La], an atomic concentration of Co is represented by [Co], and an atomic concentration of Zn is represented by [Zn].

A ferrite sintered magnet comprising an M type Sr ferrite having a hexagonal structure as a main phase, wherein the ferrite sintered magnet does not substantially comprise a rare earth element and Co, a content of B is 0.005 to 0.9% by mass in terms of B.sub.2O.sub.3, and a content of Zn is 0.01 to 1.2% by mass in terms of ZnO.

A Co.sub.2Z hexaferrite composition is provided containing molybdenum and one or both of barium and strontium, having the formula (Ba.sub.2Sr.sub.(3-Z)Co.sub.(2+X))Mo.sub.xFe.sub.(y-2x)O.sub.41 where x=0.01 to 0.20; y=20 to 24; and z=0 to 3. The composition can exhibit high permeabilities and equal or substantially equal values of permeability and permittivity while retaining low magnetic and dielectric loss tangents and loss factors. The composition is suitable for high frequency applications such as ultrahigh frequency and microwave antennas and other devices.

This ferrite sintered magnet comprises metallic elements at an atomic ratio represented by formula (1):

Ca.sub.1-w-xR.sub.wSr.sub.xFe.sub.zCo.sub.m (1) in formula (1), R is at least one element selected from the group consisting of rare-earth elements and Bi, and R comprises at least La, in formula (1), w, x, z and m satisfy formulae (2) to (5):

0.360w0.420 (2)

0.110x0.173 (3)

8.51z9.71 (4)

0.208m0.269 (5), and in a section parallel to an axis of easy magnetization, when the number of total ferrite grains is N and the number of ferrite grains having a stacking fault is n, 0n/N0.20 is satisfied.

A ferrite sintered magnet comprises a plurality of main phase grains containing a ferrite having a hexagonal structure, wherein at least some of the main phase grains are core-shell structure grains each having a core and a shell covering the core; and wherein the minimum value of the content of La in the core is [La]c atom %; the minimum value of the content of Co in the core is [Co]c atom %; the maximum value of the content of La in the shell is [La]s atom %; the maximum value of the content of Co in the shell is [Co]s atom %; [La]c+[Co]c is 3.08 atom % or more and 4.44 atom % or less; and [La]s+[Co]s is 7.60 atom % or more and 9.89 atom % or less.

The present invention produces a ferrite magnetic material having a remarkably higher maximum energy product ((BH).sub.max) than a conventional ferrite magnetic material through the induction of a high saturation magnetization and a high anisotropic magnetic field by simultaneously adding Co and Zn to substitute some of Fe and adjusting the content ratio of Zn/Co. In addition, the present invention can produce a desired magnetic material at a lower cost than a conventional CaLaCo-based ferrite magnetic material substituted with only Co by using Zn, which is relatively at least seven times cheaper than Co, together with Co.

Disclosed herein are doped perovskite oxides. The doped perovskite oxides may be used as a cathode material in an electrochemical cell to electrochemically generate ammonia from N.sub.2. The doped perovskite oxides may be combined with nitride compounds, for instance iron nitride, to further increase the efficiency of the ammonia production.

A multilayer ceramic substrate that includes a laminate having stacked ceramic layers formed of a ceramic material containing a main component, containing 48 to 75% by weight of Si, 20 to 40% by weight of Ba, and 10 to 40% by weight of Al, and an auxiliary component containing at least 2.5 to 20 parts by weight of Mn with respect to 100 parts by weight of the main component, and in the laminate, glass ceramic layers in which the entire or a portion of the thickness thereof exists within 100 m inside of the laminate as measured from opposed principal surfaces are further stacked.

Disclosed herein are embodiments of composite hexagonal ferrite materials formed from a combination of Y phase and Z phase hexagonal ferrite materials. Advantageously, embodiments of the material can have a high resonant frequency as well as a high permeability. In some embodiments, the materials can be useful for magnetodielectric antennas.

The invention relates to a method for preparing a composite metal oxide hollow fibre. A certain stoichiometry of composite metal oxide raw material and a polymer binding agent are added to an organic solvent, and mixed mechanically to obtain an evenly dispersed spinning solution having a suitable viscosity. After defoaming treatment, the spinning solution is extruded through a spinneret and, after undergoing a certain dry spinning process, enters an external coagulation bath; during this period, a phase inversion process occurs and composite metal oxide hollow fibre blanks are formed. The blanks are immersed in the external coagulation bath and the organic solvent is displaced; after natural drying, the blanks undergo a heat treatment process; during this period, polymer burn off, in situ reaction, and in situ sintering processes occur to obtain the composite metal oxide hollow fibre.