Disclosed are embodiments of synthetic garnet materials for use in radiofrequency applications. In some embodiments, increased amounts of bismuth can be added into specific sites in the crystal structure of the synthetic garnet in order to boost certain properties, such as the dielectric constant and magnetization. Accordingly, embodiments of the disclosed materials can be used in high frequency applications, such as in base station antennas.

A two-component microwave ferrite material, a preparation method therefor and an application thereof. The two-component microwave ferrite material comprises a first microwave ferrite material and a second microwave ferrite material. The preparation method comprises the following steps: (1) mixing a first microwave ferrite material and a second microwave ferrite material according to a formula amount, and then performing wet ball milling to obtain a ball abrasive; (2) drying the ball abrasive, sieving, and granulating; and (3) sequentially forming and sintering the granulated particles obtained in step (2) to obtain a two-component microwave ferrite material.

The present invention provides a ferrite sintered magnet comprising (1) main phase grains containing a ferrite having a hexagonal structure, (2) two-grain boundaries formed between two of the main phase grains, and (3) multi-grain boundaries surrounded by three or more of the main phase grains. The above ferrite sintered magnet comprises Ca, R, Sr, Fe and Co, with R being at least one element selected from the group consisting of rare earth elements and Bi, and comprising at least La. The number Nm of the above main phase grains and the number Ng of the above multi-grain boundaries in the cross section including the direction of the easy magnetization axis of the above ferrite sintered magnet satisfy the formula (1A):

50%Nm/(Nm+Ng)65%(1A).

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 embodiments of synthetic garnet materials for use in radiofrequency applications. In some embodiments, increased amounts of bismuth can be added into specific sites in the crystal structure of the synthetic garnet in order to boost certain properties, such as the dielectric constant and magnetization. Accordingly, embodiments of the disclosed materials can be used in high frequency applications, such as in base station antennas.

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.

Disclosed are embodiments of synthetic garnet materials for use in radiofrequency applications. In some embodiments, increased amounts of bismuth can be added into specific sites in the crystal structure of the synthetic garnet in order to boost certain properties, such as the dielectric constant and magnetization. Accordingly, embodiments of the disclosed materials can be used in high frequency applications, such as in base station antennas.

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 %.

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.