How Strong Are Rare Earth Magnets?
Magnets are an integral part of many technologies and appliances in the 21st century.
From tiny fridge magnets that hold to-do lists to powerful ones that create magnetic fields for electricity generation from wind turbines, there are many different types of magnets.
The world’s strongest magnets, also known as rare earth magnets, are made by alloying certain rare earth elements with other materials.
But just how strong are rare earth magnets, and what makes them so powerful?
Measuring Magnet Strength
The above infographic uses data from First4Magnets to compare the strength of magnets. But before looking at the strongest magnets, it’s essential to understand how to measure magnetic strength.
The maximum energy product, measured in mega-gauss-oersteds (MGOe), is one of the primary indicators of magnetic strength. It is a multiplication of two measurements: a magnet’s remanence and its coercivity.
To become magnets, ferromagnetic substances need to enter the magnetic field of an existing magnet. Remanence, measured in Gauss, is the magnetism left in the magnet after removing the external magnetic field.
Coercivity is the energy required to bring a magnetic material’s magnetism down to zero. Measured in oersteds, it essentially captures the magnetic material’s resistance to demagnetization.
The Strength of Rare Earth Magnets
Each magnet has a grade, which typically denotes its strength. For example, a neodymium magnet of grade N42 has a strength of 42MGOe.
To put the power of two common rare earth magnet grades into perspective, here’s how their strength compares with common grades of other permanent magnets:
|Magnet (Grade)||Composition||Maximum Energy Product (MGOe)|
|Neodymium (N42)||Neodymium, iron, boron||42|
|Samarium Cobalt (SmCo 2:17)||Samarium, cobalt||28|
|Alnico (Alnico-5)||Iron, aluminum, nickel, cobalt||5.5|
|Ferrite (Ferrite-8)||Ceramics, iron oxide||3.5|
|Magnetic rubber (Grade Y)||Strontium or barium, synthetic rubber, PVC||0.8|
Note: While the N42 neodymium magnet is used more commonly, the strongest available magnet is of grade N52.
Neodymium and samarium—two of the 17 rare earth elements—are ferromagnetic, meaning that they have inherent magnetic properties and can be magnetized. These metals are first mined, refined, and then combined with materials like iron, boron, and/or cobalt to make the strongest magnetic alloys.
Neodymium magnets are typically composed of one-third neodymium, along with iron and boron. Some of the neodymium in magnets can be replaced with praseodymium, another rare earth material. For this reason, neodymium magnets are also known as NdPr magnets.
Due to their strength, neodymium magnets have found their way into various technologies, from phones and laptops to motors in electric vehicles. In fact, according to Adamas Intelligence, 90% of all EV motors use NdPr magnets. Because these magnets also offer relatively high strength for a smaller size, they are also the predominant choice for wind turbines, reducing turbine weight significantly.
Samarium-cobalt magnets exhibit exceptional resistance to extreme temperatures. These magnets can operate from temperatures as low as -270℃ up to 350℃ and are also highly resistant to corrosion. Consequently, they have important applications in harsh marine environments and technologies with high operating temperatures.
The Demand for Neodymium Magnets
Global EV sales more than doubled last year, up from around 3 million cars in 2020 to 6.6 million in 2021. Similarly, renewable energy is expanding at a record pace, with capacity installations in 2022 set to break the record set the previous year.
With that in mind, it’s no surprise that the demand for rare earth magnets is expected to increase. Neodymium magnet consumption is forecasted to grow from more than 100,000 tonnes in 2020 to 300,000 tonnes by 2035, with EVs and wind turbines driving growth.
However, the supply chain of neodymium magnets remains a concern with China controlling the majority of rare earth extraction, refining, and downstream magnet production.
Charted: America’s Import Reliance of Critical Minerals
The U.S. is heavily reliant on imports for many critical minerals. How import-dependent is the U.S. for each one, and on which country?
Charting America’s Import Reliance of Key Minerals
The push towards a more sustainable future requires various key minerals to build the infrastructure of the green economy. However, the U.S. is heavily reliant on nonfuel mineral imports causing potential vulnerabilities in the nation’s supply chains.
Specifically, the U.S. is 100% reliant on imports for at least 12 key minerals deemed critical by the government, with China being the primary import source for many of these along with many other critical minerals.
This graphic uses data from the U.S. Geological Survey (USGS) to visualize America’s import dependence for 30 different key nonfuel minerals along with the nation that the U.S. primarily imports each mineral from.
U.S. Import Reliance, by Mineral
While the U.S. mines and processes a significant amount of minerals domestically, in 2022 imports still accounted for more than half of the country’s consumption of 51 nonfuel minerals. The USGS calculates a net import reliance as a percentage of apparent consumption, showing how much of U.S. demand for each mineral is met through imports.
Of the most important minerals deemed by the USGS, the U.S. was 95% or more reliant on imports for 13 different minerals, with China being the primary import source for more than half of these.
|Mineral||Net Import Reliance as Percentage of Consumption||Primary Import Source (2018-2021)|
|Graphite (natural)||100%||🇨🇳 China|
|Indium||100%||🇰🇷 Republic of Korea|
|Rare Earths (compounds and metals)||95%||🇨🇳 China|
|Titanium (metal)||95%||🇯🇵 Japan|
|Chromium||83%||🇿🇦 South Africa|
|Aluminum (bauxite)||75%||🇯🇲 Jamaica|
|Platinum||66%||🇿🇦 South Africa|
|Zirconium||50%||🇿🇦 South Africa|
These include rare earths (a group of 17 nearly indistinguishable heavy metals with similar properties) which are essential in technology, high-powered magnets, electronics, and industry, along with natural graphite which is found in lithium-ion batteries.
These are all on the U.S. government’s critical mineral list which has a total of 50 minerals, and the U.S. is 50% or more import reliant for 43 of these minerals.
Some other minerals on the official list which the U.S. is 100% reliant on imports for are arsenic, fluorspar, indium, manganese, niobium, and tantalum, which are used in a variety of applications like the production of alloys and semiconductors along with the manufacturing of electronic components like LCD screens and capacitors.
China’s Gallium and Germanium Restrictions
America’s dependence on imports for various minerals has resulted in a new challenge resulting from China’s announced export restrictions on gallium and germanium that took effect August 1st, 2023. The U.S. is 100% import dependent for gallium and 50% import dependent for germanium.
These restrictions are seen as a retaliation against U.S. and EU sanctions on China which have restricted the export of chips and chipmaking equipment.
Both gallium and germanium are used in the production of transistors and semiconductors along with solar panels and cells, and these export restrictions present an additional hurdle for critical U.S. supply chains of various technologies that include LED lights and fiber-optic systems used for high-speed data transmission.
The restrictions also affect the European Union, which imports 71% of its gallium and 45% of its germanium from China. It’s another stark reminder to the world of China’s dominance in the production and processing of many key minerals.
The announcement of these restrictions has only highlighted the importance for the U.S. and other nations to reduce import dependence and diversify supply chains of key minerals and technologies.
Why Copper Is a Critical Mineral
From the electrical grid to EVs, copper is a key building block for the modern economy.
Why Copper is a Critical Mineral
Copper is critical for everything from the electrical grid to electric vehicles and renewable energy technologies.
But despite copper’s indispensable role in the modern economy, it is not on the U.S. Critical Minerals list.
This infographic from the Copper Development Association shows what makes copper critical, and why it should be an officially designated Critical Mineral.
Copper’s Role in the Economy
Besides clean energy technologies, several industries including construction, infrastructure, and defense use copper for its unique properties.
For example, copper is used in pipes and water service lines due to its resistance to corrosion and durable nature. As the Biden Administration plans to replace all of America’s lead water pipes, copper pipes are the best long-term solution.
Copper’s high electrical conductivity makes it the material of choice for electric wires and cables. Therefore, it is an important part of energy technologies like wind farms, solar panels, lithium-ion batteries, and the grid. The demand for copper from these technologies is projected to grow over the next decade:
|Energy Technology||Annual Copper Demand Growth (2021-2035P)||Use of Copper|
|Offshore wind||23.3%||Undersea cables, generators, transformers|
|Battery storage||21.8%||Transformers, wiring|
|Automotive*||14.0%||Batteries, motors, charging infrastructure|
|Solar PV||11.9%||Wiring, heat exchangers|
|Onshore wind||9.8%||Cabling, transformers, substations|
|Electrical transmission||7.2%||Transformers, cables, circuit breakers|
|Electrical distribution||2.7%||Transformers, cables, circuit breakers|
*excludes internal combustion engine (ICE) vehicles.
Furthermore, policies like the Inflation Reduction Act and Bipartisan Infrastructure Law will bolster copper demand through energy and infrastructure investments.
Given its vital role in numerous technologies, why is copper not on the U.S. Critical Minerals list?
Copper and the Critical Minerals List
The USGS defines a Critical Mineral as having three components, and copper meets each one:
- It is essential to economic and national security.
- It plays a key role in energy technology, defense, consumer electronics, and other applications.
- Its supply chain is vulnerable to disruption.
In addition, copper ore grades are falling globally, from an average of 2% in 1900 to 1% in 2000 and a projected 0.5% in 2030, according to BloombergNEF. As grades continue falling, copper mining could become less economical in certain regions, posing a risk to future supply.
The current USGS list of Critical Minerals, which does not include copper, is based on supply risk scores that use data from 2015 to 2018. According to an analysis by the Copper Development Association using the USGS’ methodology, new data shows that copper meets the USGS’ supply risk score cutoff for inclusion on the Critical Minerals list.
Despite not being on the official list, copper is beyond critical. Its inclusion on the official Critical Minerals list will allow for streamlined regulations and faster development of new supply sources.
The Copper Development Association (CDA) brings the value of copper and its alloys to society, to address the challenges of today and tomorrow. Click here to learn more about why copper should be an official critical mineral.
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