This ferrite sintered magnet comprises ferrite phases having a magnetoplumbite type crystal structure. This magnet comprises an element R, an element M, Fe, Co, B, Mn and Cr, the element R is at least one element selected from rare earth elements including Y, the element M is at least one element selected from the group consisting of Ca, Sr and Ba, with Ca being an essential element, and when an atomic composition of metallic elements is represented by R.sub.1-xM.sub.xFe.sub.m-yCo.sub.y, x, y and m satisfy formulae:

0.2x0.8(1)

0.1y0.65(2)

3m<14(3).

Additionally, a content of B is 0.1 to 0.4% by mass in terms of B.sub.2O.sub.3, a content of Mn is 0.15 to 1.02% by mass in terms of MnO, and a content of Cr is 0.02 to 2.01% by mass in terms of Cr.sub.2O.sub.3.

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 cathode material used in an anode and a cathode contains (Co, Fe).sub.3O.sub.4 and a perovskite type oxide that is expressed by the general formula ABO.sub.3 and includes at least one of La and Sr at the A site. A content ratio of (Co, Fe).sub.3O.sub.4 in the cathode material is at least 0.23 wt % and no more than 8.6 wt %.

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.

An electrolyte of a solid oxide cell is required to be capable of suppressing both gas cross-leak and electron leak. In addition, it is important from the viewpoint of a reduction in material costs and in the electric resistance of the electrolyte that the electrolyte is made into a thin film and that no expensive noble metal is used. The present invention provides a thin-film-shaped proton conducting electrolyte capable of suppressing both gas cross-leak and electron leak, a solid oxide cell using the proton conducting electrolyte, and a manufacturing method for the proton conducting electrolyte and the solid oxide cell. A proton conducting electrolyte using an oxide material having proton conductivity is provided. The proton conducting electrolyte includes a first portion containing Me (Me=at least any one of Ti, Mn, Fe, Co, Ni, and Cu), and a second portion different in Me content from the first portion.

A cathode material used in an anode and a cathode contains (Co,Fe).sub.3O.sub.4 and a perovskite type oxide that is expressed by the general formula ABO.sub.3 and includes at least one of La and Sr at the A site. A content ratio of (Co,Fe).sub.3O.sub.4 in the cathode material is at least 0.23 wt % and no more than 8.6 wt %.

A fuel cell has an anode, a cathode, and a solid electrolyte layer. The cathode contains a main component containing a perovskite oxide which is expressed by the general formula ABO.sub.3 and includes at least one of La and Sr at the A site. The solid electrolyte layer is disposed between the anode and the cathode. The cathode includes an interface region that is within 5 m from a surface near to the solid electrolyte layer. The interface region contains a main phase containing the perovskite oxide, and a secondary phase containing strontium oxide. An occupied surface area ratio of the secondary phase in a cross section of the interface region is greater than or equal 0.05% and less than or equal to 3%.