Category Physics

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...

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New Steel Beats the Strength-Ductilitiy Trade-off

(a) Electron backscatter diffraction (EBSD) phase image showing the lamella microstructure of layered austenite grains embedded in tempered martensite matrix. (b) The dislocation structures in martensite as enlarged in transmission electron microscopy (TEM) image. (c) TEM image showing the elongation of dislocation cell structure after the 8% tensile strain. (d) TEM image confirming the transformation of metastable austenite to martensite after 16% tensile strain. Credit: The University of Hong Kong

(a) Electron backscatter diffraction (EBSD) phase image showing the lamella microstructure of layered austenite grains embedded in tempered martensite matrix. (b) The dislocation structures in martensite as enlarged in transmission electron microscopy (TEM) image. (c) TEM image showing the elongation of dislocation cell structure after the 8% tensile strain. (d) TEM image confirming the transformation of metastable austenite to martensite after 16% tensile strain. Credit: The University of Hong Kong

Automotive, aerospace and defence applications require metallic materials with ultra-high strength...

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Carbon Nanotube Pores developed to Exclude Salt from Seawater

An artist's depiction of the promise of carbon nanotube porins for desalination. The image depicts a stylized carbon nanotube pipe that delivers clean desalinated water from the ocean to a kitchen tap. Credit: Image by Ryan Chen/LLNL

An artist’s depiction of the promise of carbon nanotube porins for desalination. The image depicts a stylized carbon nanotube pipe that delivers clean desalinated water from the ocean to a kitchen tap. Credit: Image by Ryan Chen/LLNL

Lawrence Livermore scientists, in collaboration with Northeastern University have developed a saltwater purification device. The team also found that water permeability in carbon nanotubes (CNTs) with diameters smaller than a nanometer (0.8 nm) exceeds that of wider CNTs by an order of magnitude. The nanotubes, hollow structures made of carbon atoms in a unique arrangement, are more than 50,000 times thinner than a human hair...

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No Batteries Required: Energy-harvesting Yarns generate Electricity

Coiled carbon nanotube yarns, created at the University of Texas at Dallas and imaged here with a scanning electron microscope, generate electrical energy when stretched or twisted. Credit: University of Texas at Dallas

Coiled carbon nanotube yarns, created at the University of Texas at Dallas and imaged here with a scanning electron microscope, generate electrical energy when stretched or twisted. Credit: University of Texas at Dallas

An international team led by scientists at The University of Texas at Dallas and Hanyang University in South Korea has developed high-tech yarns that generate electricity when they are stretched or twisted. In a study published in the Aug. 25 issue of the journal Science, researchers describe “twistron” yarns and their possible applications, such as harvesting energy from the motion of ocean waves or from temperature fluctuations. When sewn into a shirt, these yarns served as a self-powered breathing monitor.

“The easiest way to think of twistron harvesters is, you have a p...

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