Researchers Race to Form New Metal

The Soviets are after it. So are the Germans, the Japanese and the Dutch.

But right now, no one--not even Nature--may be as close as Professor of Physics Isaac F. Silvera to creating metallic hydrogen.

But while Silvera and his three-man research team know they are close to their goal, they are not sure what will happen if they succeed.

They may end up with a room temperature "superconductor" capable of conducting enormous electrical currents without resistance. With it "you can create enormous amounts of power without a power loss," says Silvera. Most conductors lose electrical power because of friction but a superconductor could transport electricity at super-fast speeds with greater energy efficiency.

Orthey might end up with metallic hydrogen that turns back into a gas under normal temperature and pressure.

Whatever the results, the race to create the substance is on and in the attempts to create the superconductor, scientists have devised a variety of experiments.

The Soviet scientists constructed "a massive six-story press that just staggers the mind," Silvera says, "it ended up being a white elephant."

Silvera took an entirely different approach, making his experiment small enough to fit under a microscope.

The scientists are attempting to apply millions of atmospheres of pressure to the hydrogen by squeezing the molecules between two microscopic diamond chips. By pushing the two chips together at a temperature of approximately-450 degrees, Silvera hopes to attain his goal.

with the small experiment, "I can walk around with millions of atmospheres in my pocket," Silvera says.

"It's a real revolution in high pressure technique," he says. "Because the area is so small, you don't need that much force." But the real bonus, he says, is that "the diamond gives a window on the experiment. We might actually be able to watch the hydrogen change into the metallic state."

A major concern is whether the metallic-hydrogen will return to a gas once the pressure and temperature are normalized.

While Silvera remains hopeful that it will not, other scientists remain skeptical.

"My own feeling is that it will not stay around once it is made," says Art Ruoff, a Cornell University professor who is one of the few U.S. scientists working on the same problem. "Its only value is that it is scientifically interesting to create," he adds.

To Silvers's assistants, however, the prospect of failure is not a major worry.

"You can't tell what will happen, but it's exciting and new," says Eric Eliel, one of Silvera's post-doctoral students.

"It's not important that I specifically create metallic hydrogen, but I do want to do something that requires technical inventivity."

But Silvera hopes his project will pay off. "At normal pressure and temperature, diamonds should return to carbon graphite, but it takes millions of years for it to change back." Silvera says, expressing the hope that metallic hydrogen will act the same way. "There's also an exciting prediction that it will become a liquid, which would give it some amazing properties," he adds.

The scientists admit that there is some competition among research groups around the world to attain the material, but it is a "friendly" battle, they say.

"There's a reasonable amount of competition," Cornell's Ruoff says, adding that the groups hold occasional meetings and seminars to discuss progress and exchange ideas.

"I also have great fun playing basketball with him [Silvers] at the conferences," he adds.

"We think we know what the others are up to," Eliel says, adding. "As far as competition goes, we're making a bigger investment than most groups."

But Silvers still faces several hurdles--and the toughest is creating the necessary several million atmospheres of pressure.

Until recently, it was very difficult to get 100,000 atmospheres, but with the new diamond cell, they can predictably attain at least 1 million atmospheres, Silvers says.

They are currently in the process of constructing the cell and he predicts that--provided his calculations are correct--they may attain the necessary pressure within a year.

"We're dealing with micro-units and the diamonds have to be exactly parallel," he explains, adding that there is also the complication that there is also the complication that the diamonds themselves may be unable to withstand the high pressure.

Silvera began his work on metallic hydrogen while at the University of Amsterdam, where he taught for 11 years until 1982, when he joined the Harvard faculty. He has also worked at the Roskwell International Science Center in Thousand Oaks, Calif. He received his degree from the University of California at Berkeley