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Rare Earth Magnets

Rare-earth magnets

 

CMS Magnetics has a wide variety of magnets for sale.  Our best sellers are typically our rare earth magnets which include both Neodymium Magnets & Samarium -Cobalt magnets.  These magnets come in many shapes (see below) and strengths as well as variations such as with adhesive, countersunk holes and several finishing coats.

 

Rare-earth magnets are strong permanent magnets that were developed during the 1970s & 80s.  A permanent magnet produces a magnetic field that is always on and has no off/on switch like an electromagnet.  Rare earth magnets are manufactured using “Rare Earth material which is an ore that is mined from the earth.   Two elements derived from this ore material are combined with other materials such as iron, cobalt, and boron.  These alloys have been named by their primary rare earth elements names.  Neodymium and samarium cobalt.   

These two types of rare earth magnets have been through many improvements since the late 70s to develop more strength but since their beginnings have been the strongest permanent magnets on the face of the earth.  That is even more true now because of the continual refinements made to the manufacturing process.

 

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Nd

Name  Neodymium

symbol  Nd

60

Atomic Weight  144.24

Electron configurations  

Crystalline structure 

Physical state at 68 degrees F  Solid

Family  Lanthanides 

Atomic mass Density7.0 g cm-3

Melting point 1024 °C

Boiling point 3074 °C

Isotopes9

Discovered by

Also Called ND, Neodymium - Nd Neodymium

Neodymium Alloy (used in neodymium magnets) NdFeb (Neodymium Iron & Boron)

 

Neodymium Magnets Available at CMS

 

Arc Magnets

Magnetic Cubes

Disc Magnets

Bar Magnets

Magnetic Balls

Sphere Magnets

Wedge Magnets 

Ring Magnets 

As well as Magnetic Tools, Toys & Magnetic Bracelets

 

Samarium-Cobalt Magnets Available at CMS

 

SMCO MAGNETS DISC 

SmCo Block Magnets

 

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Neodymium Strip Mine In China

15 elements are listed on the Periodic Table of the Elements that belong to the rare earth family.  On the table, they are referred to as the Lanthanides.  The 2 we are interested in are Neodymium Nd  in a cell phone Neodymium is used in the speaker, microphone, and vibration units

Mars Rovers have been using these strong magnets for dust collection (for analysis) for years

 

 melikechi-img3.jpgNeodymium     Neodymium Neodymium is a glistening silvery-yellow metal. It's quite responsive and quickly tarnishes in the atmosphere and the coat of corrosion formed doesn't protect the metal from further oxidation, so it must be kept away from contact with air. Applications

Neodymium is one of those rare chemicals that is found in homes in equipment such as televisions, 

These magnets are commonly used in

Modern vehicles (brakes & AC components)

Data storage

Household items ( magnetic hooks, knife holders, craft magnets & toys)

Loudspeakers.

 

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Neodymium 

 

Neodymium is the 2nd most abundant of these rare-earth components (after cerium) and is nearly as abundant as aluminum. Neodymium is found in minerals that have all lanthanide minerals, such as monazite and bastnasite. 

Neodymium found in humans is very small and, even though the metal has no biological function. Neodymium can be very painful if the dust or salts get into the eyes. Even ingested neodymium is only slightly toxic.

Neodymium however, can cause lung problems, particularly during long-term exposure. 

 

Neodymium magnets are extremely powerful permanent (non-electromagnets) magnets made from an alloy of neodymium, iron & boron. Two elements from the lanthanide group of elements are used in making very powerful magnets. They are Samarium & Neodymium. The elemental group Lanthanides along with two other chemically similar compounds, scandium and yttrium are collectively called Rare Earth elements. 

 

 

 

Samarium-cobalt

 

Samarium–cobalt magnets (chemical formula: SmCo5), the first family of rare-earth magnets invented, are less used than neodymium magnets because of their higher cost and lower magnetic field strength. However, samarium–cobalt has a higher Curie temperature, creating a niche for these magnets in applications where the high field strength is needed at high operating temperatures. They are highly resistant to oxidation, but sintered samarium–cobalt magnets are brittle and prone to chipping and cracking and may fracture when subjected to thermal shock.

 

Other Questions

 

What is a rare earth magnet? Rare-earth magnets are extremely strong permanent magnets?  These magnets are manufactured by combining alloy materials with Neodymium or Samarium then magnetized.  Developed in the 1970s and 1980s, rare-earth magnets are the strongest permanent magnets made.  Rare earth magnets are a huge leap forward in terms of strength over the magnets of the past & are nearly as responsible for the leap in miniaturized electronics as the integrated circuit.   

 

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How are rare earth magnets made? Rare earth magnets are created by combining Rare Earth Materials such as Neodymium or Samarium with other elements such as Iron, Boron & cobalt and then magnetizing the alloy?

  

 

How rare are rare earth magnets? The rare earth elements used to make Rare Earth Magnets are about as plentiful as aluminum?   The term “rare earth” was coined soon after discovery because everyone thought it was rare before discovering that the ore was quite plentiful. 

 

 

How much are rare earth magnets worth

There are many variables to this question of value.  First of all Rare Earth is not "rare".  It does come from China (98%)  & the whims of the Chinese government can and do affect the value or at least the cost.   Size and ammount of material is another factor. Typically a md size Bar Magnet or a Mid Sized magnetic sphere will cost about $1.00-1.50 retail.

How strong are rare earth magnets

These 2 Vidios should help with that question:

https://www.youtube.com/watch?v=6feqSNK09Ms&t=19s

Or if that does not convince you 

https://www.youtube.com/watch?v=N5vPnViHYGI

 

 More about Rare Earth Magnets

 

Some important properties used to compare permanent magnets are remanence (Br), which measures the strength of the magnetic field; coercivity (HCI), the material's resistance to becoming demagnetized; energy product (B·Hmax), the density of magnetic energy; and Curie temperature (TC), the temperature at which the material loses its magnetism. Rare-earth magnets have higher remanence, much higher coercivity, and energy product, but (for neodymium) lower Curie temperature than other types. The table below compares the magnetic performance of the two types of rare-earth magnets, neodymium (Nd2Fe14B) and samarium-cobalt (SmCo5), with other types of permanent magnets.

 

Coercivity

  

Coercivity is a measure of the ability of a magnet to withstand an external magnetic field without becoming demagnetized. Coercivity is usually measured in oersted or ampere/meter units and is denoted HC.

Both hard & soft ferromagnetic materials exist  Hard meaning that they hold their magnetism very well while the soft ferromagnetic materials tend to lose magnetism with a smaller change to their surroundings.  

Heat is a major factor, especially in the “soft” range.  Many neodymium magnets lose their magnetism at about 174 degrees Fahrenheit.   These are great for many applications like transformer and inductor cores, recording heads, microwave devices, and magnetic shielding.

Soft materials cannot be used in things like electric motors and other applications that create a very hot environment.

Magnetically hard,  are used to make permanent magnets. Materials with low coercivity are said to be magnetically soft. 

 

TEMPERATURE

Temperature sensitivity varies, but when a magnet is heated to a temperature known as the Curie point, it loses all of its magnetism, even after cooling below that temperature. 

The maximum usable temperature for SmCo, about 140 °C (280 °F) for neodymium may be less than 180 degrees F and even lower for flexible ceramics, The exact numbers depend on the grade of material.

 

 

A Rare earth element (REE) established Nd-Fe-B and Sm-Co permanent magnets are widely used due to their excellent magnetic properties.  An electric car may use up to about 9 lbs of rare-earth magnets, while one of those wind turbines that now dot our landscape use upwards of 600 pounds of specifically neodymium (Nd). 

China is the go-to country for rare earth magnets making up for over 95% of mining of rare earth ore and manufacturing of neodymium & samarium cobalt permanent magnets.  

 

You can see why this dependence on such a highly used material could create a strategic vulnerability for the United States and undermines our national security, competitiveness in the defense, clean-energy sectors & consumer electronics.  Rare earth shortages also can cause significant supply-chain issues for U.S. technology companies.  

Hence, the recycling of infrequent earth-based magnets has gained increasing attention and significance from the permanent magnet industry. Up to now, only very little amounts of REEs have been recycled out of pre-consumer magnet scrap. The objective of the project is to create a scalable, efficient, and low-cost manufacturing method to recycle infrequent earth-based magnets from industrial scrap into precious magnetic alloys and high-performance magnets with tailored properties for certain applications.


Neodymium is part of the rare earth family of elements listed on the periodic table of the elements. Neodymium creates awesomely powerful magnets. Samarium Cobalt is the other material that is part of the rare earth family from which rare earth magnets are manufactured.

 properly. Little magnets should always be kept away from small children and pets, as they can cause serious harm if they're swallowed. Very strong magnets, like neodymium magnets, can pull together with an extremely substantial force, pinching your fingers if they're caught in between. You always need to keep magnets away from digital devices, such as computers and mobile phones, and away from credit cards (or any other card with a magnetic strip). This is because the information on such devices can be stored using a magnetic recording, and maybe erased when it comes close to a strong magnetic field.