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NATURE NONE Periodic Table SCI TECH TECH_Technology

Liquid metal could help lead to faster electronics

A team of researchers from RMIT University have uncovered a new technique to make atomically thin flakes of different materials, a process that could lead to faster, more efficient electronics.

In this method, certain metals are dissolved in liquid metal. Then, the resulting super-thin oxide layer is peeled off and can be used for various purposes. While it has not been extensively tested yet, the technique is predicted to work on roughly one-third of the periodic table.

As a proof of concept, scientists have used the method to create hafnium oxide with a thickness of just three atoms. That is roughly five to ten times thinner than hafnium oxide layers produced with other techniques. To get that thinness, researchers worked with the material for 18 long months.

“Here we found an extraordinary, yet very simple method to create atomically thin flakes of materials that don’t naturally exist as layered structures,” said study co-author Dr Torben Daeneke, a researcher at RMIT’s School of Engineering, according to Gizmodo Australia.

To do this, scientists use non-toxic alloys of gallium — a metal similar to aluminum — as a reaction medium to cover the surface of the liquid metal with atomically thin oxide layers of the added metal rather than the naturally occurring gallium oxide. Then, they exfoliate the oxide layer by touching the liquid metal with a smooth surface. Not only that but, as gallium alloy is liquid at room temperature, the process can be done safely at ambient conditions.

The new research is important because it could help scientists create semiconducting and dielectric components. Both of those are key for a lot of current technology. By making such components extremely thin, the team may be able to create stronger, more energy efficient electronics. The products could have applications in devices like batteries as well.

“The most important outcome of our work is that we introduce liquid metals as a reaction solvent which opens the door to a whole new type of chemistry,” added Daeneke, according to Yahoo News.

The recent findings are outlined in the journal Science.

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NATURE NONE Periodic Table SCI Science

Ancient elements show how Earth’s crust developed over time

Researchers from the the University of Chicago looked into Earth’s geological past and found new evidence as to why our planet is able to sustain life, a new study published in the journal Science reports.

The best way to study the history of the world is to look at its elements. In the research, scientists traced the path of the metallic element titanium back through time. This revealed that significant tectonic movement took place before 3.5 billion years ago, which is roughly half a billion years earlier than currently thought.

Earth’s crust used to be comprised of uniformly dark, magnesium- and iron-rich mafic minerals. However, today’s crust is now a lighter-colored rock made up of felsic elements, such as silicon and aluminum. Figuring out when that transition occurred is important because mineral composition affects the flow of nutrients that help organisms thrive and grow.

To shed light on the topic, scientists looked at how titanium developed in shales — rocks made up of tiny bits of other rocks and minerals that are carried by water into mud deposits — over time. The element does not dissolve in water and it is not taken up by plants in nutrient cycles. As a result, it does not muddy the data like research on other elements.

The team crushed up shale rock samples from different ages and then noted the amounts of titanium at each period. While they expected to see large shifts, the team found little change over three-and-a-half billion years. That means the large changes must have taken place that time.

This is important because, not only does it gives new information on the development of Earth’s crust, but it could also help shed light on the origin of plate tectonics.

“Our results can also be used to track the average composition of the continental crust through time, allowing us to investigate the supply of nutrients to the oceans going back 3.5 billion years ago,” said lead author Nicolas Greber, a postdoctoral researcher at the University of Chicago who is now working at the University of Geneva, in a statement.

The study of ancient nutrients could also enable scientists to better understand the turning point known as the Great Oxidation Event, where oxygen started to move out into the Earth’s atmosphere.

That period — one of the most important in history — gave rise to a surge of photosynthetic microorganisms that helped bring a surge of nutrients into the oceans. The new titanium timeline outlined in the study suggests the primary mechanism behind that surge came from the shift in rocks in the Earth’s crust.

“This question has been discussed since geologists first started thinking about rocks,” said lead author Nicolas Dauphas, a professor at the University of Chicago, according to Phys.org. “This result is a surprise and certainly an upheaval in that discussion.”

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New research could mean safer storage and recycling of radioactive material

A team of researchers led by Florida State Professor Thomas Albrecht-Schmitt believe that they have found a way to make the storage of radioactive waste safer and to recycle nuclear fuel.

The researchers found that element californium, Cf on the Periodic Table of Elements, has shown a remarkable ability to bond and separate other materials in carefully controlled experiments. The tests also showed that californium was extraordinarily resistant to radiation damage.

“It’s almost like snake oil. It sounds almost too good to be true. This has real world application. It’s not purely an academic practice,” said Albrecht-Schmitt in a statement.

The findings, published in the latest edition of Nature Chemistry, demonstrates that californium could be used to make new, safer storage containers for radioactive waste. The element could also be used to separate radioactive fuel, which would allow it to be recycled.

There is, however, a downside. Californium is both expensive and rare. After several years of working with the U.S. Department of Energy, Albrecht-Schmitt was able to obtain five milligrams of californium at a cost of $1.4 million from the Oak Ridge National Laboratory.

Californium is a metallic chemical element that is itself radioactive. Cf was first made in 1950 at the University of California, Berkeley. It is created by bombarding curium with alpha particles. It has the second highest atomic mass of any element that can be seen with the naked eye and, although it can be synthesized, it is the heaviest naturally occurring element on Earth.

Additional information about the chemical properties of Californium is available from the Thomas Jefferson National Accelerator Facility (Jefferson Lab).

Although it may be rare and expensive to synthesize, safer nuclear storage and nuclear fuel recycling would be welcomed by many following the Fukushima disaster and a recent radiation leak at a New Mexico storage facility.

According to the Nuclear Energy Institute, the U.S. Department of Energy is responsible for the storage and long-term management of waste from U.S. nuclear power plants. There is, however, no long-term plan in place for the storage or recycling of fuel from commercial nuclear facilities.

Fast Company’s Co.exist blog states that “120 million Americans live within 50 miles of a nuclear reactor.” Additionally, the Nuclear Regulatory Commission lists a total of 55 Independent Spent Fuel Storage Installations (ISFSIs) in 33 states as of March, 2012. Still, more Americans live on or near transportation routes used to move nuclear waste from plants to storage facilities. Getting maps of these routes though is difficult because of security concerns.

If Thomas Albrecht-Schmitt’s research can improve the safety of nuclear waste storage, while decreasing the amount of waste through recycling, government, industry and the civilian population could all breathe a little easier.