Rare Earth Based Iron Garnet – A Survey on Its Magnetic Properties

Abstract

Abstract Garnet is a well-known material for a long-time by the scientific community but still today scientists are focusing on it due to the rapid application-based development of this material. When rare earth iron garnets (REIG) are formed by substituting the rare-earth ions with unfilled 4fn orbitals, the magnetic properties of the iron garnets exhibit an interesting characteristic. For rare earth elements, the 4f electrons are shielded from the crystal field as these are surrounded by 5s, 5p, or 5d orbitals. That is why the exchange field between rare earth ions is much smaller than that between iron-iron and rare earth-iron. The magnetic moment of REIG will be both due to the orbital and spin moment. The magnetization of REIG at different temperatures (T) is due to the dominant contribution of different sublattices. At high and low T, the dominant sublattices are iron and rare earth sublattices respectively. The magnetic and non-magnetic ion substitution in REIG also play a very important role in deciding their magnetic property. In this review, we have tried to figure out the basic underlying physics behind the origin of remarkable magnetic behavior in REIG.