Complex oxides have long tantalized the materials science community for their promise in next-generation energy and information technologies. Complex oxide crystals combine oxygen atoms with assorted metals to produce unusual and very desirable properties.
Researchers at the Department of Energy’s Oak Ridge National Laboratory got a surprise when they built a highly ordered lattice by layering thin films containing lanthanum, strontium, oxygen and iron. Although each layer had an intrinsically nonpolar (symmetric) distribution of electrical charges, the lattice had an asymmetric distribution of charges. The charge asymmetry creates an extra “switch” that brings new functionalities to materials when “flipped” by external stimuli such as electric fields or mechanical strain. This makes polar materials useful for devices such as sensors and actuators.
On Tuesday, Feb. 18, President Obama unveiled the timing for the next phase of fuel economy regulations for trucks. He delivered his speech at a Safeway store in Maryland.
After an illustrious 36-year career, energy policy research analyst David Greene retired late last year from The Department of Energy's Oak Ridge National Laboratory.