Soft Ferrite Magnets, Soft Ferrites, Soft Ferrite Core, Nickel- Zinc ferrites, MnZn ferrite, microwave ferrites

HSMAG manufactures soft ferrite cores (Soft Ferrite Magnets) in both MnZn and NiZn to most of the IEC standard shapes and sizes. Material permeabilities range from 15 to 15000 in grades specialized for RF, signal, power and suppression applications. Custom shapes and sizes are available upon requests.

Soft Ferrite Magnets Cores

Soft Ferrite Magnets Cores

Types of Materials and Available Shapes of Cores

Soft Ferrite. Soft ferrites are derived from iron oxide obtained from the cleaning of steel (pickle liquor) or mined from the earth. Metals such as nickel, manganese and zinc are added to the iron oxide.

Ferrite material is then pressed and fired to form a crystalline structure that gives ferrite cores their soft magnetic properties. Subsequent grinding or coating operations may take place before the core is used. Manganese-Zinc soft ferrites have high permeability and low eddy current losses; Nickel- Zinc ferrites have lower permeabilities with very low eddy current losses.
A variety of materials spans the frequency range from 10 KHz to 1 GHz and up. Soft ferrites have low saturation flux densities, in the range of 2500 to 4000 gauss, but are available in shapes that can be readily gapped to handle more MMF at the sacrifice of permeability. Because of their very low core loss at high frequency, ferrites are used extensively in switchmode power supplies as power transformers, filter inductors, current transformers, and mag amps. Ferrites are available in a wide variety of shapes and sizes with volumes up to about 500 cm. Some other common applications for ferrites are rod antennas, common mode filters, RF trans- formers, and pure inductors.

Ferrites were plagued for many years by their extremely wide physical and magnetic tolerances. Additionally, ferrites are hindered by rather large temperature dependence. Extensive research and development has improved, but not eliminated, all of the soft ferrite shortcomings. Because of their widespread manufacture, low cost, and readily available technical information, soft ferrites are the most widely used magnetic material at High- Frequency.

At high frequency metallic soft magnetic materials simply cannot be used due to the eddy current losses. Therefore, soft ferrites, which are ceramic insulators, become the most desirable material. These materials are ferrimagnetic with a cubic crystal structure and the general composition MO.Fe2O3, where M is a transition metal such as nickel, manganese or zinc.

MnZn ferrite, sold commercially as ferroxcube, can be used at frequencies up to 10MHz, for example in telephone signal transmitters and receivers and in switch mode power supplies (also referred to as DC-DC converters). For these type of application the driving force to increase frequency is to allow miniaturisation.

Additionally, part of the family of soft ferrites, are the microwave ferrites, e.g. yttrium iron garnet. These ferrites are used in the frequency range from 100MHz to 500GHz, for waveguides for electromagnetic radiation and in microwave devices such as phase shifters.