A team overseen by University of Minnesota Twin Cities experimenters has found out how subtle structural modifications in strontium titanate, a metal oxide semiconductor, can modify the material’s electrical resistance and influence its superconducting properties.
Strontium titanate has existed on scientists’ radar for 60 years because it exhibits many interesting properties.
It serves as a superconductor and conducts electricity smoothly without resistance when kept under low temperatures and low concentrations of electrons. It also withstands a structural modification at 110 Kelvin, suggesting that the atoms in its crystalline configuration alterat their arrangement. Scientists are still discussing what results in superconductivity in this material on the microscopic level or what occurs when its structure changes.
The researchers successfully made this finding because they were competent to synthesize a strontium titanate material that was incredibly “clean,” implying that it contained very few impurities. They utilized a technique named hybrid molecular beam epitaxy (MBE) to attain this, and it was a technique that Jalan’s lab initiated.
“The practical response of the superconducting properties to small differences in the density of electrons gives new pieces in the ongoing puzzle of superconductivity in strontium titanate,” said the University of Minnesota School of Physics and Astronomy Professor and contributing author Rafael Fernandes. His organization handled the theoretical modeling aspect of the research.
“A lot of questions in modern science and engineering are so complex that they exceed a single discipline,” Pribiag said. “Having these collaborations available within the same college is extremely useful. You need all of these ingredients to solve a lot of problems.”