Related topics: magnetic properties

Toward more efficient computing, with magnetic waves

MIT researchers have devised a novel circuit design that enables precise control of computing with magnetic waves—with no electricity needed. The advance takes a step toward practical magnetic-based devices, which have ...

Quantum transition makes electrons behave as if they lack spin

The common phase transitions are those that occur as a function of temperature variation. Ice changes phase to become liquid water at 0 degrees Celsius. Liquid water changes phase to become water vapor at 100 degrees Celsius. ...

Magnetic tuning at the nanoscale

In collaboration with colleagues from the Leibniz Institute for Solid State and Materials Research Dresden (IFW) and the University of Glasgow, physicists from the German research center Helmholtz-Zentrum Dresden-Rossendorf ...

Suspended layers make a special superconductor

In superconducting materials, an electric current will flow without any resistance. There are quite a few practical applications of this phenomenon; however, many fundamental questions remain as yet unanswered. Associate ...

Laser pulses create topological state in graphene

Discovering ways to control the topological aspects of quantum materials is an important research frontier because it can lead to desirable electrical and spin transport properties for future device technologies. Now MPSD ...

Bringing ideas to life through experimental physics

Even the most brilliant scientific ideas need data. Just this year, the first-ever image of a black hole finally provided the evidence needed to support Einstein's 100-year-old theories. 

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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