Related topics: magnetic properties

Shape-encoded dynamic assembly of mobile micromachines

Field-directed and self-propelled colloidal assembly can be used to build micromachines to perform complex motions and functions, although their integration as heterogenous components with specified structures, dynamics and ...

Theory explains ferromagnetic superconductor behavior

Researchers from France and Russia have offered a theoretical explanation for the behavior of a recently discovered material combining superconducting and ferromagnetic properties. The new theoretical model also predicts ...

Nanoporous material nets contaminant from water

Barely visible material that looks like tiny grains of sand may hold the key to removing an invisible health threat that has contaminated water supplies across the country. Researchers at Pacific Northwest National Laboratory ...

A peculiar ground-state phase for 2-D superconductors

The application of large enough magnetic fields results in the disruption of superconducting states in materials, even at drastically low temperature, thereby changing them directly into insulators—or so was traditionally ...

Experimental physicists redefine ultrafast, coherent magnetism

Electronic properties of materials can be directly influenced via light absorption in under a femtosecond (10-15 seconds), which is regarded as the limit of the maximum achievable speed of electronic circuits. In contrast, ...

Approaching the magnetic singularity

In many materials, electrical resistance and voltage change in the presence of a magnetic field, usually varying smoothly as the magnetic field rotates. This simple magnetic response underlies many applications including ...

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Magnet

A magnet (from Greek μαγνήτις λίθος magnḗtis líthos, "Magnesian stone") is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials and attracts or repels other magnets.

A permanent magnet is one made from a material that stays magnetized. An example is a magnet used to hold notes on a refrigerator door. Materials that can be magnetized, which are also the ones that are strongly attracted to a magnet, are called ferromagnetic (or ferrimagnetic). These include iron, nickel, cobalt, some rare earth metals and some of their alloys (e.g. Alnico), and some naturally occurring minerals such as lodestone.

Although ferromagnetic (and ferrimagnetic) materials are the only ones with an attraction strong enough to a magnet to be commonly considered "magnetic", all other substances respond weakly to a magnetic field, by one of several other types of magnetism.

An electromagnet is made from a coil of wire which acts as a magnet when an electric current passes through it, but stops being a magnet when the current stops. Often an electromagnet is wrapped around a core of ferromagnetic material like steel, which enhances the magnetic field produced by the coil.

The overall strength of a magnet is measured by its magnetic moment, while the local strength of the magnetism in a material is measured by its magnetization.

This text uses material from Wikipedia, licensed under CC BY-SA