[neilep (OP)]

Dearest Magnetologists,

As a sheepy I of course luff magnets !.....from the moment I open my eyes to the time I go to bed they monopolise my every waking moment. Out of all the things surrounded by a magnetic field 'magnets' are right up there as my all time fave.

Look here are some that I have sexed up with snazzy special FX !


 [ Invalid Attachment ]
Magnets Sexed Up With Special FX Just Moments Ago.


Nice eh ?

What I would like to know is ...do magnets lose their magnetism over time ?...do they  just wear out ?  As a firm believer in empirical  study I am going to keep an eye on my magnets and will report here any appreciable loss of magnetism !...

Perhaps in the mean time ewe can indicate how long I'm likely to be observing my magnets ?..a few days ?...maybe as long as a few weeks ..lol...yes...as if !!


ta



neil
Ewe're Attractive
xxxxxxxxxxxxxxx

[evan_au]

Strong permanent magnets are made of a "hard" magnetic material, which is initially magnetised in a strong magnetic field. This treatment takes the magnetic material away from it's lowest energy state. These magnets will demagnetise slowly over time as they return to their lowest energy state (or immediately, if they are heated above their Curie Temperature).
http://en.wikipedia.org/wiki/Neodymium_magnet#Magnetic_properties

http://www.ehow.com/how-does_5166377_magnet-lose-its-magnetism.html suggests that some types of magnets might lose 1% of their magnetism per decade.

Magnetite is sometimes found as a "Natural" magnet, but this mineral is mostly not magnetic; some suggest it is made magnetic by a nearby lightning bolt  http://en.wikipedia.org/wiki/Lodestone

[neilep (OP)]

Strong permanent magnets are made of a "hard" magnetic material, which is initially magnetised in a strong magnetic field. This treatment takes the magnetic material away from it's lowest energy state. These magnets will demagnetise slowly over time as they return to their lowest energy state (or immediately, if they are heated above their Curie Temperature).
http://en.wikipedia.org/wiki/Neodymium_magnet#Magnetic_properties

http://www.ehow.com/how-does_5166377_magnet-lose-its-magnetism.html suggests that some types of magnets might lose 1% of their magnetism per decade.

Magnetite is sometimes found as a "Natural" magnet, but this mineral is mostly not magnetic; some suggest it is made magnetic by a nearby lightning bolt  http://en.wikipedia.org/wiki/Lodestone

Sweet !!... thank ewe evan_au really interesting !...I don't know what my magnets are made from....will need to find out now because I want to know !  []

[damocles]

http://en.wikipedia.org/wiki/Neodymium_magnet

These magnets are a glassy ceramic material Nd₂Fe₁₄B. They are usually coated with an outer layer of another more robust ceramic, because the material is reputedly quite brittle. Cigar shaped magnets like those pictured can be found on sale in toyshops etc. here.

[neilep (OP)]

http://en.wikipedia.org/wiki/Neodymium_magnet

These magnets are a glassy ceramic material Nd₂Fe₁₄B. They are usually coated with an outer layer of another more robust ceramic, because the material is reputedly quite brittle. Cigar shaped magnets like those pictured can be found on sale in toyshops etc. here.

Yes..they are the ones... thank you very much Damocles...... they are pretty fun to play around for a while !

[CZARCAR]

i thinx heat can demagnetize

[Bored chemist]

NdFeB magnets are not generally glassy. They have a well defined crystal structure.
Also the material has a metalic electrical conductivity  I don't think you can call them ceramic.
It's difficult to tell for certain but I think Neil's magnets are magnetite or ferrite which is pretty much a ceramic.
http://en.wikipedia.org/wiki/Ferrite_(magnet)

[RD]

... It's difficult to tell for certain but I think Neil's magnets are magnetite or ferrite which is pretty much a ceramic.
http://en.wikipedia.org/wiki/Ferrite_(magnet)

Awesome Iron Oxide (Fe203)

http://www.amazon.co.uk/Tobar-PowerBuzz-Magnets/dp/B00369T36E/ref=pd_sim_k_h_b_cs_1

[damocles]

I stand corrected!

A local outlet had these in a rack as "rare earth magnets" -- guess the trade descriptions police will be after him soon.