Magnetism and Magnetic Materials
The force of attraction acting from a distance is known as Magnetism. Magnetic field is produced by the movement of electrically charged particles. North and south poles are two poles in a magnet. Opposite poles of two magnets will attract each other and like poles will repel each other. In magnets and electric currents, magnetism symbolizes to the attraction of iron and other metals. In everyday life paramagnetic, diamagnetic, and antiferromagnetic materials are often described as non-magnetic as the force of a magnet on is usually too weak to be felt and can be detected only by laboratory instruments.
The origin of magnetism lies in the orbital and spin motions of electrons and how the electrons interact with one another. The magnetic behavior of materials can be categorized into the following groups:
Diamagnetism is an essential property of all matter, though it is usually very weak. It is due to the non-cooperative conduct of orbiting electrons when exposed to an applied magnetic field. Diamagnetic substances are composed of atoms which have no remaining magnetic moments (ie., all the orbital shells are filled and there are no unpaired electrons). But, when exposed to a field, a negative magnetization is formed and therefore the susceptibility is negative.
Paramagnetism materials, some of the irons or atoms in the material have a net magnetic moment due to unpaired electrons in incompletely filled orbitals. One of the significant atoms with unpaired electrons is iron. However, distinct magnetic moments do not interrelate magnetically, and like diamagnetism, the magnetization is zero when field is detached. In the existence of a field, there is now a partial configuration of the atomic magnetic moments in the direction of the field, resultant in a net positive magnetization and positive susceptibility.
Ferromagnetism is the simple mechanism by which some materials form permanent magnets, are attracted to magnets. In physics, distinct types of magnetism are distinguished. Ferromagnetism is the strongest type it is the only one that naturally creates forces strong enough to be felt, and in charge of the common phenomena of magnetism in magnets that happens in everyday life. In ionic compounds, such as oxides, additional complex forms of magnetic ordering can happen as an outcome of the crystal arrangement. One kind of magnetic ordering is called ferrimagnetism. Materials which are not attracted to the magnet are called non-magnetic materials
Materials that display antiferromagnetism, the magnetic moments of atoms, commonly related to the spins of electrons, align in a systematic pattern with neighboring spins directing in opposite directions. This is, like ferromagnetism and ferrimagnetism, an appearance of ordered magnetism. Normally, the antiferromagnetic order may exist at appropriately low temperatures, disappearing at and above a certain temperature, the Neel temperature Above the Neel temperature, the material is naturally paramagnetic.
- Spintronics and Magnetization Dynamics
- Hard and Soft Magnetic Materials
- Functional Magnetic Materials
- Magnetoelectronic Materials and Multiferroic Materials