Magnetisera

Magnetisera is the process of imparting or increasing magnetic properties in a material by aligning its internal magnetic moments. In ferromagnetic and ferrimagnetic substances, microscopic regions called domains become oriented under an external magnetic field, producing a net magnetization. When the field is removed, some alignment may remain, resulting in remanent magnetization. The ease and extent of magnetization depend on the material’s composition, crystal structure, and magnetic anisotropy.

Methods to magnetize a material include applying a strong magnetic field via permanent magnets or through electrical current in coils to create an electromagnet. Thermal treatment, such as field annealing, can orient magnetic anisotropy and improve coercivity. Mechanical processing like rolling or drawing can influence the domain structure and magnetic texture. Materials may reach saturation magnetization at high fields, after which further field increase yields little additional magnetization.

Common magnetized materials include iron, nickel, cobalt and their alloys (for example Alnico and Permalloy), as well as rare-earth magnets such as NdFeB and SmCo. Some materials are paramagnetic or diamagnetic and do not retain magnetization once the external field is removed. Magnetic properties are described by magnetization (M), saturation magnetization (Ms), remanent magnetization (Br), and coercivity (Hc), often represented by a hysteresis loop.

Applications of magnetized materials span electrical machines, transformers, electric motors, loudspeakers, magnetic storage media, sensors, and medical imaging. Magnetic properties can be measured with magnetometers and by tracing hysteresis curves. The field is central to materials science, with ongoing research aimed at improving energy efficiency, durability, and performance of magnetic devices.