Introduction to Soft Ferrite Magnets

Magnets are often characterized as either soft ferrite or hard ferrite. Both soft ferrite and Hard Ferrite Magnet are typically made of a ceramic material. That`s why they are known as [ferrites." Ferrites are magnetic compounds consisting primarily of iron oxide that`s mixed with other metals, some of which may include zinc, nickel, barium and manganese. Iron oxide is mixed with some of these other metals to create ferrite, which is then used to create a ferrite magnet. Some ferrite magnets, however, are soft, whereas others are hard.

Soft ferrites are not Permanent Ferrite Magnets. They carry magnetism (like mild steel) but as soon as the magnetic field is removed, the magnetism disappears. Soft ferrites are popular as transformers (to change the voltage from primary to secondary windings). So soft ferrites are often called transformer ferrites.

Soft ferrites exist as toroids (rings), C shapes, E-shapes, curved shapes, etc. Other shapes are possible. They often have performance criteria such as permeability and inductance.

Advantages & Disadvantages of Soft Ferrite Magnets

Advantages

- Carry magnetism effectively with low losses

- Can handle alternating currents

Disadvantages

- Have different properties such as inductance and permeability so care is required to get a correct material type

- It will be expected that the customer knows exactly what they require

The Differences Between Hard Ferrite Magnet and Soft Ferrite Magnet

Hard Magnets

The ferrite used in permanent magnets is hard ferrite, which has high coactivity and reminisces after magnetization. Iron oxide and barium carbonate or strontium carbonate are used to make hard ferrite. Because of their high coactivity, hard ferrites are not easily demagnetized, which is an important characteristic of permanent magnets. Hard ferrites can produce magnetic flux and also have a high magnetic permeability. Hard ferrites, also known as Ceramic Ferrite Magnets, are inexpensive and are commonly used in household products (e.g. refrigerator magnets).

Soft Magnets

Ferrites used in transformers or electromagnet cores that include nickel; zinc or manganese compounds have a low coactivity and are generally referred to as soft ferrites. The low coactivity means that the magnetization strength of the material can be changed from positive to negative without consuming much energy (hysteresis), and the high resistivity of the material itself reduces another source of energy loss: the generation of eddy currents. Due to the low losses at high frequencies, it is commonly used in the cores of RF transformers and in the reactors used in switching power supplies.