The Lanthanum In Your Lens

Why it takes most of the periodic table to make an iPhone, and why many of those elements aren't mined in the U.S. today.
Blog Post
Flickr: Gadgetmac // Nest Photo
June 16, 2016

One of the wonders of smartphones is that they are so small. It isn't just that they are powerful computers, but that they can take sharp pictures, play music at reasonably loud volumes, and vibrate forcefully when they need to grab your attention. Another wonder is that they are so cheap, given their capabilites. For the most part, iPhones are assembled in China (there is also one factory in Brazil). For MIT Technology Review, I asked whether it would be possible to make iPhones in the U.S.

If you are willing to accept a dependence on foreign raw materials, manufacturing an iPhone in the U.S., while difficult, is a tractable problem - they would only cost a little bit more. But the small size of iPhones is because to make an iPhone, you need almost 2/3rds of the elements on the periodic table. The iPhone's small size means that it would be very difficult to make an iPhone out of American raw materials.

Without hafnium, for instance, the transistors on a microchip would have to be three to four times bigger. Hafnium is used in small amounts in the “gate oxide,” a thin layer that is like a door that opens or closes, allowing electricity to flow or not, and so performing the basic logical functions necessary for computing. Hafnium is a rare transition metal; so-called "rare earths" are also needed.

Neodymium, for instance, is needed to create powerful magnets. Without neodymium magnets an iPhone would have to be 10 to 15 times larger, says Alex King of the Department of Energy's Critical Materials Institute. The biggest magnet in an iPhone is the magnet that powers the motor that makes it vibrate. But even if you imagine a phone that had no vibrate mode, magnets are needed for both the speaker and the microphone. Without neodymium, these would be much larger, and so would the phone. Neodymium alone isn’t enough, because a magnet made of neodymium iron boron (a standard configuration) would be vulnerable to getting demagnetized if it got hot. So you need to add dysprosium, another rare earth, as well, to make it more resistant to losing its magnetization.

Lanthanum, another rare earth, is needed in the iPhone’s camera lens. It increases the refractive index, allowing a tiny lens to collect and focus a lot of light. “If you didn’t have lanthanum, the lens on your iPhone would look like the lens on an SLR,” says King. China produced about 85% of the world’s rare earths in 2014, according to the U.S. Geological Survey.

Lithium is used in the batteries in iPhones and other mobile phones. 96% of U.S. lithium imports come from Chile and Argentina. In 2013, the U.S. produced only 870 tons of lithium, as opposed to 11,200 tons from Chile and 4,700 in China. Then there are materials needed to make phones that aren’t in the actual phones - like cerium, which is needed to polish the silicon and metal on both the insides and outsides of phones.

An ambitious plan by a company called Molycorp to reduce American dependency on Chinese sources of rare earths is stalled for the moment after the company declared bankruptcy in 2015. Molycorp was counting on a mine in Mountain Pass, California to be the source of rare earths. “If the quality of the geology were the deciding factor, then probably the Mountain Pass mine would be the dominant source in the world,” King told me. In other words, in a national emergency, the U.S. could gear up to produce rare earths domestically, but can’t compete with China. In part this is because Baotou, the principal Chinese rare earth mine, is also an iron mine, and so can extract rare earths at far lower costs than the Mountain Pass mine could.

Making an iPhone from "American atoms" is next to impossible. The only good news is that there is plenty of silicon; reserves, the USGS says, are ample.