ABSTRACT
Transformer cores are constructed predominantly from ferromagnetic material. The most commonly used material is iron, with the addition of small amounts of silicon and other elements that help improve the magnetic properties and/or lower losses. Other materials, such as the nickel–iron alloys and the iron oxides, are used in electronic transformers. The amorphous metals, generally consisting of iron, boron, and other additions, are also used as cores for distribution transformers. Cores made of silicon steel are constructed using multiple layers of the material in sheet form. Atomic magnetism results from a combination of both orbital and electron moments. In some materials, the atomic magnetic moments either cancel each other or are very small so that little material magnetism results. This chapter expresses the relationship between saturation magnetization and absolute temperature. Magnetostriction is actually a fairly complex phenomenon and can exhibit hysteresis as well as anisotropy.
