Geologist identifies new form of quasicrystal

LOWELL, Mass. – A UMass Lowell geologist is among the researchers who have discovered a new type of manmade quasicrystal created by the first test blast of an atomic bomb.

The formation holds promise as a new material that could one day help repair bone, insulate heat or convert heat to electricity, among other uses, according to UMass Lowell Prof. G. Nelson Eby, a member of the university’s Environmental, Earth and Atmospheric Sciences Department.

Eby is a member of the research team that identified the quasicrystal substance inside samples of trinitite they examined that were collected from the debris of the first atomic bomb detonated by the U.S. Army on July 16, 1945 in the New Mexico desert. Also known as atomic rock, trinitite is a glassy material produced by the extreme heat and pressure unleashed by detonated atomic devices. The rock gets its name from the word “trinity,” the U.S military’s code term for the first nuclear test blast.

Naturally occurring quasicrystals have been found in meteorites and in structures impacted by meteorite strikes; researchers first discovered them in aluminum-manganese alloy in the early 1980s. While scientists have created quasicrystals in the laboratory since then, their discovery in trinitite represents the first known time the substance was artificially created, according to Eby, who lives in Burlington.

The quasicrystal the researchers discovered in the trinitite is shaped in an icosahedron, a solid, 3D structure with 20 faces. The material is composed of silicon, copper, calcium and iron that can be traced to source materials near the bomb site that were drawn into the enormous force of the explosion along with the desert sand.

“Quasicrystals are strange crystalline forms that do not follow the normal laws of crystal symmetry. The tremendous pressure and temperature generated by an atomic detonation can lead to new forms of quasicrystals, such as the one we identified that cannot be produced in a laboratory,” Eby said.

The research team’s findings were published last month in the academic journal Proceedings of the National Academy of Sciences. Along with Eby, scientists from the University of Florence in Florence, Italy; the California Institute of Technology; Los Alamos National Laboratory; Princeton University; and a researcher working independently contributed to the project.

Eby believes the growing understanding of the conditions under which various types of quasicrystals form can help scientists design them for specific purposes, such as heat insulation, converting heat into electricity, bone repair and use in prosthetics, he said.

An understanding of trinitite, which Eby and his students study in his UMass Lowell laboratory, is also vital, according to Eby.

“Because of concerns about the proliferation and possible use of atomic weapons by rogue nations and terrorist groups, over the past decade, forensic studies of radioactive elements contained in trinitite have been conducted by a number of academic and federal laboratories and institutions, including UMass Lowell,” he said.

Such study is essential should scientists be called upon to assist in investigations of atomic activity, according to Eby.

“Materials recovered from a detonated atomic device would most likely contain remnants of the bomb, and knowing the relationship between glass chemistry and radioactive elements in the materials would be useful in characterizing the device and ultimately identifying the perpetrators,” he said.

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