Liquid metal could help lead to faster electronics

Researchers have found a technique that creates extremely thin metal for use in 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.

Scientists detect gravitational waves produced by colliding neutron stars

Ability to observe an event via both gravitational waves and light is a revolution for modern astronomy.

Scientists using the Laser Interferometer Gravitational Wave Observatory (LIGO) observatory have for the first time detected gravitational waves produced by a collision of two neutron stars in the galaxy NGC4993, located in the constellation Hydra.

Predicted in 1916 by Albert Einstein’s general theory of relativity, the ripples in the fabric of spacetime known as gravitational waves were first detected a century later by LIGO, caused by the merger of two black holes.

That detection led to three scientists winning the 2017 Nobel Prize in physics.

While gravitational waves have subsequently been detected several times since then, this is the first time they were observed coming from merging neutron stars rather than merging black holes.

Neutron stars are the stellar remnants of massive stars that died in supernova explosions. Extremely massive stars that die in supernova explosions leave behind black holes while less massive stars that die in these explosions produce neutron stars, which have cores somewhat less massive than black holes.

These extremely dense cores are capable of crushing protons and electrons to form neutrons.

Although neutron stars are small, with diameters of around 12 miles (19 km), they can be as dense as our Sun and have masses up to one billion tons.

Unlike black holes, which have gravitational pulls so strong that even light cannot escape them, neutron stars, in merging, emit light in multiple wavelengths.

This means their mergers can be observed both by the gravitational waves they produce and in various wavelengths of light.

Approximately 130 million years ago, two stars of between eight and 20 solar masses in the galaxy NGC4993 underwent supernova explosions, then orbited one another until they collided.

On August 17, LIGO and Virgo detected the gravitational waves produced by the collision, and a few minutes later, NASA’s Fermi space telescope observed a flash of gamma rays the explosion produced.

Once the gamma rays were detected, scientists knew the direction from which the gravitational waves came, and astronomers worldwide aimed telescopes at the phenomenon to collect additional data.

The double detection confirms that both light and gravitational waves travel at the same universal speed of light, another Einstein prediction.

“This event has the most precise sky localization of all detected gravitational waves so far,” said Virgo spokesman Jo van den Brand. “This record precision enabled astronomers to perform follow-up observations that led to a plethora of breathtaking results.”

More than 3,500 astronomers worldwide observed the event with over 70 telescopes.

Researchers studying the light spectra of material emitted during the merger found the fingerprints of heavy elements, including gold, platinum, and lead, confirming theories that the periodic table’s heaviest elements are forged in mergers of neutron stars.

 

Ancient elements show how Earth’s crust developed over time

A new study on the history of the Earth’s crust gives new insight into how our planet supports life.

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.”