Nanoscale technology could play an important role in developing materials for future electronics applications, with the help of nanoscale sensors to measure stresses on materials under high pressure.
The researchers reported their findings in the journal Science. The paper, titled “Imaging stress and magnetism at high pressures using a nanoscale quantum sensor,” describes how the researchers fit a series of nanoscale sensors—termed as nitrogen-vacancy color centers—into diamonds used to exert high pressures on tiny material samples. Typically, those “diamond anvil” experiments with materials squeezed between two diamonds have allowed researchers to measure pressure and changes in volume.
Understanding those changes could lead to new materials or new phases of matter for use in all kinds of technologies and applications, said Valery Levitas, a paper co-author and Anson Marston, Distinguished Professor in Engineering at Iowa State University, the Vance Coffman Faculty Chair and professor in aerospace engineering. Levitas worked with the paper’s lead author Norman Yao, an assistant professor of physics at the University of California, Berkeley. Iowa State’s Mehdi Kamrani, a doctoral student in aerospace engineering, is also a co-author.
The new system allows researchers to image, measure and calculate six different stresses—a much more comprehensive and realistic measure of the effects of high pressure on materials. The new tests also allow researchers to measure changes in a material’s magnetism.
“This has been one of the key problems in high-pressure science,” Levitas said. “We need to measure all six of these stresses across a diamond and sample. But it’s hard to measure all of them under high pressure." Levitas’ lab has done unique experiments by putting materials under high pressure and then giving them a twist, allowing researchers to drastically reduce phase transformation pressure and search for new phases of matter, which may have technological applications.
The sensor enables “pursuit of two complementary objectives in high-pressure science: understanding the strength and failure of materials under pressure and discovering and characterizing exotic phases of matter,” the researchers wrote in their paper.
The nitrogen-vacancy sensing technology described in the paper has also been used to measure other material properties—for example, electric and thermal characteristics. The researchers wrote it “can now straightforwardly be extended to high-pressure environments, opening up a large range of experiments for quantitatively characterizing materials at such extreme conditions.”