PORTLAND, Ore. -- Rare earth materials are becoming increasingly rare as dominant supplier China tightens restrictions on production, essentially cutting already short-supply exports by a third.
As a result, rare earth prices are skyrocketing in a market where supply can only meet only about 40 percent of the demand outside China, according to a recent report from rare earths expert Dudley Kingsnorth, executive director of the Industrial Minerals Co. of Australia.
"Prices for rare earths are going wild," said Mike Pugh, director of operations for Intematix Corp. "For instance, the price of europium more than doubled during a three-week period in June of this year."
The U.S., Canada and Australia all have strategic efforts underway to reopen rare earth mines outside China, including new mines in Russia and Malaysia. Still, these new mines are not expected to significantly reduce the shortfall for at least three years. As a result, hoarding and price gouging are already rampant as is a concerted effort by manufacturers to either move manufacturing operations to China or find alternatives to rare earths.
Rare earths are used in slurries for mechanical planarization of everything from glass to semiconductor wafers. Chip makers are resorting to silicates and other minerals to substitute for rare earths, but the biggest squeeze is being felt by makers of phosphors for everything from fluorescent bulbs to white LEDs.
Phosphor maker Intematix (Fremont, Calif.) is taking a two-prong approach to rare earth shortages--moving some of its manufacturing to China while developing alternate phosphors in the U.S.
"By manufacturing our aluminate and garnet phosphors in China, we can buy our rare earth materials there instead of having to export them," said Pugh. "In the U.S., we are making our nitride and silicate phosphors which use only very small quantities of rare earths."
Intematix manufactures its aluminates (green) and garnets (yellow) in China to side-step export restrictions, but makes its rare-earth-light nitrides (red) and silicates (yellow, orange) in its U.S. production facility.
These nitride- and silicate-based phosphors can substitute for the heavily rare-earth-doped aluminate and garnet phosphors that are traditionally used for fluorescent bulbs and white LEDs, thus sidestepping the rare earth scarcity problem, but at a price. Nitride-based phosphors, for instance, are more than three times as expensive as traditional aluminate- and garnet-phosphors, both of which are heavily doped with rare earth materials.
"When you get a quote on the price of nitride phosphors it knocks your socks off," said Pugh. "But when you realize how little you need of them they become very affordable."
One bright spot in the rare earth market is that shortages may accelerate the move to solid-state lighting since much less phosphor is needed to coat the inside of an LED compared to a fluorescent bulb. A blue LED can be used to pump green silicate phosphors mixed with red and yellow nitride phosphors to make white light. That combination uses few rare earths.
Nitride phosphors, in particular, are very rugged, allowing them to be placed very close to the semiconductor junction of a blue LED, further reducing the amount of material needed to make white light.