Quick, what do you know about lanthanum, praseodymium, neodymium, or dysprosium? If you said they are chemical elements, you are right: numbers 57, 59, 60, and 66, to be exact. They and their neighbors on the periodic table, collectively “rare earths,” were once mere curiosities tucked in between barium and tungsten. Now they’re having their day in the sun, thanks to new technology, as did uranium and plutonium when atomic energy was developed. The military may begin stockpiling them.

Good idea or not?

My first encounter with these elements was a project that developed high-tech shock absorbers to protect a replacement camera for the Hubble telescope during the camera’s rough ride to orbit. These devices, called M-Struts, pioneered the use of permanent magnets for shock mitigation. The only material our team found that would provide sufficient magnetic flux density (a measure of the strength of a magnetic field at a given point) was a rare earth alloy, NdFeB (neodymium-iron-boron). This material could only be procured from China.

M-Struts were a one-off project that had no discernible effect on the demand curve for neodymium. But now the demand curve is crowding up against the supply curve largely because of rare earth applications in “green” energy devices such as wind turbines (extra points if you knew that). Continue reading →