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📷 | You can take pictures like never before !? Weighing only 68g “stick” camera stand “Hookpod”


You can take pictures like never before !? "Hookpod", a camera stand that weighs only 68g and "sticks"

If you write the contents roughly
Neodymium magnets are so powerful that they can be used without problems if they weigh up to about 10 kg.

For those who enjoy photography and video, the second most important tool after a camera is a tripod.Only ... → Continue reading


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Neodymium magnet

Neodymium magnet(Neodymium magnet,English: Neodymium magnet) Isneodymium,鉄,BoronIs the main componentRare earth magnetOne of (rare earth magnets).permanent magnetIt is said to be the most powerful of all.1984ToAmerica OfGeneral Motorsas well as the JapanSumitomo Special Metals (currentlyHitachi Metals)ofMasato SagawaInvented by[1][2]..The prime minister is Nd2Fe14B. It is sometimes referred to as "neodymium magnet", but it is a mistake.


Magnetic flux densityIs high and very strongMagnetic forcehave.MagneticThe strength of is graded from N24 to N54 (theoretically up to N64). The number after N represents the strength of the magnet.Even if the size is several cm, it has an adsorption force of 10 kgf or more, so do not pinch your fingers when handling it.glovesIt is necessary to do.


The range of products used is wide, from small to large.An example of a large product isElectric train-Electric car-Hybrid car-エ レ ベ ー タ ーFor drivingPermanent magnet synchronous motor OfFieldand so on.

An example of a small product isHard disk drive,CD player,Mobile phoneAnd so on.On hard disk drivesheadFor moving a read / write device calledActuatorUsed for.

Harder in audio equipmentDamperIt is said that a tight bass is produced because it can be adopted, and in recent yearsHeadphones OfdriverIt is used in many of.Since a strong magnetic field can be obtained even if the size is reduced, it is indispensable especially for small earbud and canal type headphones.

Disadvantages and countermeasures

In addition to being mechanically fragile, it is also prone to thermal demagnetization when heated (Curie temperatureHas the drawback of about 315 ° C).As a countermeasure,dysprosiumAddCoercive forceThere are methods to improve. It is said that the addition of 1% dysprosium improves thermal demagnetization by 15 ° C.Since dysprosium is a rare resource, neodymium magnets have recently been used instead of dysprosium.crystalResearch is being conducted to improve thermal demagnetization by reducing the particle size.[3].

But neodymiumoxygenIf the crystal grains of the magnet are made smaller, the surface area that comes into contact with air will increase.Spontaneous combustionI have something to do.Therefore, it is necessary to manufacture in an environment excluding oxygen.In addition, it is very rusty and when used as a productnickelでPlatingIt is often done.


[How to use footnotes]
  1. ^ M. Sagawa; et al. (1984). “Permanent Magnet Materials based on the Rare Earth-Iron-Boron Tetragonal Compounds (Invited)”. IEEE Transactions on Magneticsw MAG-20 (5): 1584-1589. NOT 80002298568. 
  2. ^ Masato Sagawa, Masaaki Hamano,Makoto HirabayashiHen "Permanent Magnets: Materials Science and Applications" Agne Technology Center, 2007.ISBN 978-4-901496-38-4.
  3. ^ "Development of high-performance magnets with TDK halving neodymium content". Nihon Keizai Shimbun(July 2014, 10). http://www.nikkei.com/article/DGXMZO77909700T01C14A0000000/ 2015th of February 10Browse. 

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