Magnetics

A ferromagnetic material consists of many small magnetic domains, which are, themselves, magnetized (quantum mechanical phenomenon). A piece of steel that is magnetized, has those domains in alignment, which is a higher energy configuration, while the piece of steel that is not magnetized, has those domains out of alignment, which is a lower energy configuration. It is very common to store some energy in the magnetic field inside the ferromagnetic material; the device which does so is called 'inductor', and most inductors use field inside ferromagnetic material.

Again ferromagnetism is the basic mechanism by which certain materials (such as iron) form permanent magnets, or are attracted to magnets. In physics, several different types of magnetism are distinguished. Ferromagnetism (including ferrimagnetism) is the strongest type: it is the only one that typically creates forces strong enough to be felt, and is responsible for the common phenomena of magnetism in magnets encountered in everyday life. We are moding and inventing different types of harnessing magnetism, paramagnetism, diamagnetism, and antiferromagnetism, but the forces are usually so weak that they can only be detected by sensitive instruments in a laboratory.  continue...