How to demagnetize a magnet temporarily? - Physics Stack …
2015年2月17日 · You should take an electromagnet that operates on some frequency (tens of Hertz) and creates enough large magnetic field to magnetise your permanent magnet. Then you switch on your electromagnet in the vicinity of the permanent magnet and go slowly back from the permanent magnet at the distance of several meters.
Why does a magnet loose magnetic strength when heated?
2016年4月15日 · Magnet manufacturing companies, for example Dexter Magnetic Technologies do not hesitate to explain the effects of heat upon magnets - citing how it degenerates the magnetic properties with levels of reversible and irreversible demagnetization. However, they gloss over the "Why" of this phenomenon comparatively quickly.
Do Magnets ever lose their magnetism, and if so how long does it …
2015年11月4日 · One can use a permanent magnet to magnetize iron for example. The energy needed for the ordering of magnetic dipoles in the unmagnetized material is taken from the potential energy of the oriented dipoles, demagnetizing them slowly. So how long it takes to demagnetize a permanent magnet depends on the process that induced demagnetization.
Do magnets wear out? - Physics Stack Exchange
2018年6月12日 · Demagnetize a Magnet by Heating or Hammering. If you heat a magnet past the temperature called the Curie point, the energy will free the magnetic dipoles from their ordered orientation. Heating and hammering can happen when the magnet is used to mechanically move objects, or in a dynamo, due to friction and induced magnetic effects in ...
electromagnetism - Why ferrite magnets demagnetize easier at …
2022年1月20日 · Nevertheless it is interesting to know that you possible could demagnetize a ferrite magnet nearly to zero field strength much easier and convenient by putting it to the fridge at say -20 C° than exposing it to 450C° temperatures and higher which could also physically damage the ferrite magnet.
demagnetizing a magnet - Physics Stack Exchange
2019年6月10日 · Suppose I have a powerful electromagnet with a C shaped core. In the gap of the C core is a permanent magnet, contained in a box where it may flip freely. When the electromagnet is turned on, it produces a field that is greater than the permanent magnet's coercive force, i.e. a magnetic field that could demagnetize the permanent magnet.
electromagnetism - Extra strong magnet which doesn't …
2015年10月29日 · So you make a 'magnet' that actually consists, in essence, of lots of strips of alterating N-S and S-N bar magnets. If you are very close to the magnets (such as the metal clasp of the phone case that is attracted to the magnet to hold it closed), you get the full effect of each magnet, because each point of the metal is very close to one magnet.
Hammering to form a magnet - Physics Stack Exchange
2022年7月2日 · But it likely won't fall into that stablest state. There are many other meta-stable states, with many counter-oriented domains, and it is much likelier to fall into one of these states, depending on the size of the magnet (nanomagnets tend to have fewer domains). This would be a "demagnetized" magnet.
electromagnetism - Can I Demagnetize a ferromagnet with a …
EDIT (10/15/2013): I am afraid I have similar problems with the edited question. Your statement "If an iron is exposed to an external magnetic field, the iron's domains are all aligned with that ext-B" is not universally correct. For example, a permanent magnet's magnetization typically does not follow the direction of the Earth's magnetic field.
Does the "demagnetizing" field inside a bar magnet try to actually ...
2021年12月23日 · Indeed, in the middle of a bar magnet the field is nearly zero but that does not mean that the domains are fluctuating or even effected for the molecular field that is frozen within a mesoscopic magnetic domain is orders of magnitude larger than anything we can generate form the outside. Since the direction of the polarization of these domains ...