Photosensitive Perovskites Change Shape when Exposed to Light

The perovskite material changes size when exposed to light.

The perovskite material changes size when exposed to light. Reproduced with permission from reference 1.© 2017 WILEY‐VCH Verlag GmbH & Co.

A crystalline material that changes shape in response to light could form the heart of novel light-activated devices. Perovskite crystals have received a lot of attention for their efficiency at converting sunlight into electricity, but new work by scientists at KAUST shows their potential uses extend far beyond the light-harvesting layer of solar panels. Photostriction is the property of certain materials to undergo a change in internal strain, and therefore shape, with exposure to light...

Read More

Flipping the Switch on Ferroelectrics

Charge screening in ferroelectric Pb(Zr,Ti)O3 nanorods was used to control their domain pattern. The c-domain fraction markedly increased with as the rod width decreased, while the a-domain formation prevailed by metallization of their sidewall. All the observed results could be explained by the depolarizing field, arising from the imperfect charge screening. This approach could be expanded to other low-dimensional nanoscale ferroelectric systems. Credit: Tomoaki Yamada

Charge screening in ferroelectric Pb(Zr,Ti)O3 nanorods was used to control their domain pattern. The c-domain fraction markedly increased with as the rod width decreased, while the a-domain formation prevailed by metallization of their sidewall. All the observed results could be explained by the depolarizing field, arising from the imperfect charge screening. This approach could be expanded to other low-dimensional nanoscale ferroelectric systems. Credit: Tomoaki Yamada

Scientists have taken control of the configuration of domains in nanorod- and thin-film ferroelectric systems. Many next-generation electronic and electro-mechanical device technologies hinge on the development of ferroelectric materials...

Read More

40 years on, Voyager still Hurtles through space

Artist's concept of NASA's Voyager spacecraft. Credit: NASA/JPL-Caltech

Artist’s concept of NASA’s Voyager spacecraft. Credit: NASA/JPL-Caltech

Are we alone? Forty years ago, NASA rocket scientists sought to answer this question by launching the Voyager spacecraft, twin unmanned spaceships that would travel further than any human-made object in history. When Voyager 1 and 2 launched about two weeks apart in 1977 from Cape Canaveral, Florida, scientists knew little about the outer planets in our solar system, and could hardly imagine the scope of their upcoming space odyssey.

“None of us knew, when we launched 40 years ago, that anything would still be working, and continuing on this pioneering journey,” said Voyager project scientist Ed Stone...

Read More

Elevated Zinc and Germanium levels Bolster Evidence for Habitable Environments on Mars

This view from the Mast Camera (Mastcam) on NASA’s Curiosity Mars rover shows a site with a network of prominent mineral veins below a cap rock ridge on lower Mount Sharp. The APXS instrument on Curiosity discovered unusual material in these veins that has the highest germanium concentrations found in Gale Crater. Credit: NASA

This view from the Mast Camera (Mastcam) on NASA’s Curiosity Mars rover shows a site with a network of prominent mineral veins below a cap rock ridge on lower Mount Sharp. The APXS instrument on Curiosity discovered unusual material in these veins that has the highest germanium concentrations found in Gale Crater. Credit: NASA

New data gathered by the Mars Curiosity rover indicates a potential history of hydrothermal activity at Gale Crater on the red planet, broadening the variety of habitable conditions once present there, scientists report in a new study. Researchers found concentrations of the elements zinc and germanium to be 10 to 100 times greater in sedimentary rocks in Gale Crater compared to the typical Martian crust.

Zinc and germanium tend to be enriched together in high temp...

Read More