IBM Optimizes Material Capabilities at ALS

1. IBM Optimizes Material Capabilities at ALS • Scientific Achievement • IBM researchers used the ALS to understand the link between electron conduction and lattice distortions in spintronics materials. • Significance and Impact • The ability to control electron conduction can form the basis for an ultrafast electronic switch in the future; devices could be activated so quickly that very little energy would be lost through dissipation. • Research Details • Vanadium dioxide is one of the few known materials that acts like an insulator at low temperatures but like a metal at warmer temperatures. • By varying the thickness of an underlying buffer layer, researchers were able to change the strain in a vanadium dioxide film and thereby vary the transition temperature between conducting and insulating phases. • Researchers found that the material's ordering temperature is determined by the orbital occupancy in the high-temperature metallic phase rather than that of the insulating phase. • Work was performed at Lawrence Berkeley National Laboratory, ALS Beamline 4.0.2. The operation of the ALS is supported by the U.S. Department of Energy, Office of Basic Energy Sciences. A schematic of the crystal structures in vanadium dioxide (VO2), showing the motion of the vanadium (black arrows) with respect to the oxygen ions across the metal-insulator transition. VO2 acts like an insulator at low temperatures but like a metal at near room temperature. Read the full article: www-als.lbl.gov/index.php/science-highlights/industry-als/888