High Pressure, Matter at Extreme States

Washington, DC—Recovered minerals that originated in the deep mantle can give scientists a rare glimpse into the dynamic processes occurring deep inside of the Earth and into the history of the planet’s mantle layer. A team led by the Geophysical Laboratory's Yingwei Fei, a experimental petrologist, and Cheng Xu, a field geologist from Peking University, has discovered that a rare sample of the mineral majorite originated at least 235 miles below Earth’s surface.

High Pressure, Materials

Washington, DC—It would be difficult to overestimate the importance of silicon when it comes to computing, solar energy, and other technological applications. (Not to mention the fact that it makes up an awful lot of the Earth’s crust.) Yet there is still so much to learn about how to harness the capabilities of element number 14.

The most-common form of silicon crystallizes in the same structure as diamond. But other forms can be created using different processing techniques. New work led by the Geophysical Laboratory's Tim Strobel and published in Physical Review Letters shows that one form of silicon, called Si-III (or sometimes BC8), which is synthesized using a high-pressure process, is what’s called a narrow band gap semiconductor.

High Pressure

Washington, DC—Hydrogen is both the simplest and the most-abundant element in the universe, so studying it can teach scientists about the essence of matter. And yet there are still many hydrogen secrets to unlock, including how best to force it into a superconductive, metallic state with no electrical resistance.

High Pressure

Washington, DC— New work from a team including the Geophysical Laboratory's Guoyin Shen and Yoshio Kono used high pressure and temperature to reveal a kind of “structural memory” in samples of the metal bismuth, a discovery with great electrical engineering potential.

Bismuth is a historically interesting element for scientists, as a number of important discoveries in the metal physics world were made while studying it, including important observations about the effect of magnetic fields on electrical conductivity. 

Mineralogy

Washington, DC—Human industry and ingenuity has done more to diversify and distribute minerals on Earth than any development since the rise of oxygen over 2.2 billion years ago, experts say in a paper published today. The work bolsters the scientific argument to officially designate a new geological time interval distinguished by the pervasive impact of human activities: the Anthropocene Epoch.

Planetary Science

Washington, DC—New work from the Geophysical Laboratory’s Stephen Elardo and Anat Shahar shows that interactions between iron and nickel under the extreme pressures and temperatures similar to a planetary interior can help scientists understand the period in our Solar System’s youth when planets were forming and their cores were created. Their findings are published by Nature Geoscience.

Washington, DCIn Earth’s interior, water (H2O) plays an important role in rock physics, but geoscientists rarely treat water in its constituent forms, that is as hydrogen plus oxygen. New work from a team led by the Geophysical Laboratory's Dave Mao has identified that hydrogen can escape from the water under conditions found in Earth’s lower mantle leading to a new paradigm in lower mantle chemistry. Their results were published in Proceeding of the National Academic Science, U.S.A.

High Pressure, Matter at Extreme States

Washington, DC— Although helium is the second most-abundant element (after hydrogen) in the universe, it doesn’t play well with others. It is a member of a family of seven elements called the noble gases, which are called that because of their chemical aloofness—they don’t easily form compounds with other elements. Helium, widely believed to be the most inert element, has no stable compounds under normal conditions. 

High Pressure

Washington, DCPhase transitions surround us—for instance, liquid water changes to ice when frozen and to steam when boiled. Now, researchers at the Geophysical Laboratory have discovered a new phenomenon of so-called metastability in a liquid phase. A metastable liquid is not quite stable. This state is common in supercooled liquids, which are liquids that cool below the freezing point without turning into a solid or a crystal.

High Pressure, Materials

Washington, DC—Germanium may not be a household name like silicon, its group-mate on the periodic table, but it has great potential for use in next-generation electronics and energy technology.

Of particular interest are forms of germanium that can be synthesized in the lab under extreme pressure conditions. However, one of the most-promising forms of germanium for practical applications, called ST12, has only been created in tiny sample sizes—too small to definitively confirm its properties.

Pages