Magnetic susceptibility: An easy approach to the spin-reorientation transition

Fundamental experiments in magnetism deal with phase transitions. A well-known example is the transition from ferro-to paramagnetism which is commonly observed via the magnetic susceptibility. The susceptibility is defined as the response of magnetization due to the alteration of a magnetic field. Close to the Curie temperature TC the magnetization tends to zero on the average as the ordering effect of the exchange interaction is compensated by the disconcerting action of thermal fluctuations of the spins. Above TC , the ferromagnet becomes paramagnetic. This transition features a very well-pronounced susceptibility peak 1‐ 4 that can be eas