Hydrogen responds to pressure and temperature extremes differently. Under ambient conditions hydrogen is a gaseous two-atom molecule. As confinement pressure increases, the molecules adopt different states of matter -- like when water ice melts to liquid. Scientists have now combined hydrogen with its heavier sibling deuterium and created a novel, disordered, 'Phase IV'-material. The molecules interact differently than have been observed before, which could be valuable for controlling superconducting and thermoelectric properties of new materials.
Scientists have used atomic-resolution Z-contrast imaging and X-ray spectroscopy in a scanning transmission electron microscope to explore dislocations in the binary II-VI semiconductor CdTe, commercially used in thin-film photovoltaics. The results may lead to eventual improvement in the conversion efficiency of CdTe solar cells. These novel insights into atomically resolved chemical structure of dislocations have potential for understanding many more defect-based phenomena.
Physicists have built a tractor beam that can repel and attract objects, using a hollow laser beam, bright around the edges and dark in its center. It is the first long-distance optical tractor beam, 100 times larger than previous ones.