48 Scientific American, October 2019
M
addury Somayazulu, an experimental phySiciSt who goeS by
Zulu, could only hope that being close would be good
enough. In an equipment-crammed room at Argonne
National Laboratory in Illinois, he was huddled with post-
doctoral researcher Zachary Geballe over a plum-sized
cylindrical gadget called a diamond anvil cell. Inside was a
dust speck’s worth of the rare-earth metal lanthanum and
a bit of hydrogen gas, which theorists had predicted could morph into a novel compound under
the enormous pressure of 2.1 million atmospheres. That is more than half the pressure at the
center of Earth and, more relevant on that June 2017 day, near the limits of the cell’s capacity to
compress its contents between its two pebble-sized diamonds—among the hardest materials in
nature. As the scientists turned the cell’s screws up to 1.7 million atmospheres, they felt them
tighten. The diamonds, already warped by the pressure, could break. “Okay, that’s it. We can’t
go any higher,” Somayazulu said. “Let’s try to synthesize here and see what happens.”
The scientists had surrounded the anvil cell with a kind of
high-tech firing squad: two long tubes for bombarding it with
x-rays, a constellation of lenses and mirrors for blasting it with
a laser, and a video camera to record the assault. They hoped
that once activated, the laser would catalyze the lanthanum-
hydrogen reaction. Outside the room, behind a sliding metal
door that shielded them from the x-rays, the scientists watched
a computer screen showing a graph of the x-rays’ assessment of
their mixture’s microscopic structure. The plot quickly assumed
the desired shape. They had successfully crushed and blasted
lanthanum hydride, or LaH 10 , into existence. “We were shocked,”
Somayazulu says. “We didn’t even have to heat it much and it
formed the compound”—and not just any compound.
Theory and computer modeling had suggested that LaH 10
could be a superconductor, a material with the uncanny ability
to conduct electricity without the energy losses that bedevil
conventional wires. This efficiency allows a prodigious amount
of current to be packed into a small space and circulate, perpet-
ual-motion style, forever. Better yet, LaH 10 was supposed to
work this magic at about 44 degrees Fahrenheit (280 kelvins), a
far higher temperature than achieved by any known supercon-
ductor and tantalizingly close to room temperature, a long-
standing goal. The frigid conditions required by existing super-
conductors have tended to limit their use to niche applications
such as MRI machines and particle accelerators. But a room-
temperature superconductor might be put to many more uses,
including transporting solar and wind energy to greater dis-
tances than currently practical, increasing the capacity of
creaking power grids, making batteries that never lose their
charge, and countless others in computers and medicine.
The x-ray analysis that Somayazulu and Geballe received
indicated that the LaH 10 they had created showed the exact
microscopic structure theorists had predicted. “That hit us,”
Somayazulu told me during a recent visit to Argonne, where he
joined the staff in May. When he and his colleagues synthesized
LaH 10 , he was still working for the Geophysical Laboratory of
the Carnegie Institution for Science in Washington, D.C. His
boss at the time, Russell Hemley, calls LaH 10 “a beautiful exam-
ple of materials by design.” Hemley led the team that created
the compound, as well as the theoretical group that predicted
Bob Henderson is an independent writer based in upstate
New York. He has a doctorate in high-energy theoretical
physics from the University of Rochester and has made
his living at various times as a photojournalist, an electrical
engineer, and a financial derivatives quant and trader.
IN BRIEF
Scientists dream of creating a superconductor—
a material that can conduct electricity without re-
sistance—that can function at room temperature.
To date, all require cold temperatures and some-
times high pressures.
Historically, researchers have discovered new su-
perconductors through trial and error, but recent
breakthroughs have come from theoretical algo-
rithms that use new tools, such as machine learn-
ing, to predict novel superconducting materials.
Physicists hope that theory improvements and ex-
perimental expertise may help them discover more
useful superconductors, which could expand the reach
of renewable energy technologies, improve power
grids and allow for batteries that never lose charge.
