Embodiments of synthetic garnet materials having advantageous properties, especially for below resonance frequency applications, are disclosed herein. In particular, embodiments of the synthetic garnet materials can have high Curie temperatures and dielectric constants while maintaining low magnetization. These materials can be incorporated into isolators and circulators, such as for use in telecommunication base stations.

Disclosed herein are embodiments of an enhanced resonant frequency hexagonal ferrite material and methods of manufacturing. The hexagonal ferrite material can be Y-phase strontium hexagonal ferrite material. In some embodiments, strontium can be substituted out for a trivalent or tetravalent ion composition including potassium, thereby providing for advantageous properties.

Disclosed herein are embodiments of an enhanced resonant frequency hexagonal ferrite material and methods of manufacturing. The hexagonal ferrite material can be Y-phase strontium hexagonal ferrite material. In some embodiments, strontium can be substituted out for a trivalent or tetravalent ion composition including potassium, thereby providing for advantageous properties.

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.

Provided is a ferrite sintered magnet including a ferrite phase having a magnetoplumbite-type crystal structure. x, y, and m satisfy the following Equations (1), (2), and (3) when composition of the ferrite sintered magnet is represented by R.sub.1-xA.sub.xFe.sub.m-yCo.sub.y, where R denotes at least one kind of element selected from rare earth elements including Y and A denotes Ca or Ca and elements including at least one kind selected from Sr or Ba. The content of B in the ferrite sintered magnet is from 0.1% to 0.6% by mass in terms of B.sub.2O.sub.3.

0.2≤x≤0.8  (1)

0.1≤y≤0.65  (2)

3≤m≤14  (3)

Disclosed herein are embodiments of an enhanced resonant frequency hexagonal ferrite material and methods of manufacturing. The hexagonal ferrite material can be Y-phase strontium hexagonal ferrite material. In some embodiments, strontium can be substituted out for a trivalent or tetravalent ion composition including potassium, thereby providing for advantageous properties.

Disclosed herein are embodiments of an enhanced resonant frequency hexagonal ferrite material and methods of manufacturing. The hexagonal ferrite material can be Y-phase strontium hexagonal ferrite material. In some embodiments, strontium can be substituted out for a trivalent or tetravalent ion composition including potassium, thereby providing for advantageous properties.

Provided is a red mud-based composite calcium ferrite and a preparation method and use thereof. The preparation method of the red mud-based composite calcium ferrite includes the following steps: mixing red mud and a calcium source, and roasting an obtained mixture in an oxygen-containing atmosphere to obtain the red mud-based composite calcium ferrite; where the calcium source is selected from the group consisting of lime and calcium carbonate. In the present disclosure, the composite calcium ferrite is prepared using a solid waste red mud, with a greatly reduced cost of raw materials; on the other hand, compared with traditional calcium ferrite, the composite calcium ferrite mainly has phase structures of CaFe.sub.2O.sub.4, Ca.sub.2FeAlO.sub.5, and Ca.sub.2Fe.sub.2O.sub.5. Therefore, the composite calcium ferrite has a lower melting point, a higher lime dissolution efficiency, and better fluxing and dephosphorization effects during primary smelting and refining of molten steel, and has broad prospects for use in industry.

A method of obtaining a nickel zinc cobalt spinet ferrite in ceramic form that includes the following: obtaining a precipitate (1) of iron, nickel, zinc, and cobalt hydroxides by co-precipitation, rinsing the precipitate (2), drying and grinding (3) the rinsed precipitate in order to obtain a powder; forming (4) into a compact by pressing the powder, and sintering (5) the compact. The sintering (5) includes a progressive temperature rise of 2° C. to 4° C. per minute, from an ambient temperature to reach a maximum temperature comprised between 950° C. and 1.010° C., maintaining at the maximum temperature for forty-five minutes to three hours, a progressive fall in temperature of 2° C. to 4° C. per minute to reach ambient temperature. The foregoing and, in particular, the sintering, enable a material to be obtained that is particularly well-adapted to the manufacture of an antenna configured for frequencies less than one gigahertz.

Disclosed herein are embodiments of an enhanced resonant frequency hexagonal ferrite material and methods of manufacturing. The hexagonal ferrite material can be Y-phase strontium hexagonal ferrite material. In some embodiments, sodium can be added into the crystal structure of the hexagonal ferrite material in order to achieve high resonance frequencies while maintaining high permeability.