Snowflake zinc crystals, the strongest material and "hellish planet"

Snowflake zinc crystals, the strongest material and “hellish planet”

It’s starting to feel a lot lighter

Australian researchers have grown zinc crystals that look like snowflakes inside liquid gallium metal. But you won’t be hanging them on your Christmas tree anytime soon, instead these complex symmetrical zinc crystals can potentially be used in a range of catalysis applications.

Often resembling six-pronged snowflake crystals, the structures could be adapted to suit a range of different inputs. For example, by increasing the temperature or the time it takes for them to grow, the size of the crystals could also be increased.

Higher temperatures also produced many more 12-pointed structures, which occur when two overlapping hexagonal seed crystals grow simultaneously. High pressure (5 bar) gave simple fractal shapes.

Being able to grow crystals with specific facets is important for their use in catalysis.

Zinc crystals
Images of zinc crystals obtained after one day (left), 10 days (middle) of growth at an initial temperature of 350°C and one day of growth at an initial temperature of 550°C (right) showing the changes in their shape over time. Credit: Dr Jianbo Tang

“In some catalytic reactions, for example in the conversion of carbon dioxide, this happens much faster on one facet of the crystal compared to another,” says Dr Jianbo Tang, a researcher at the School of Chemical Engineering and chemical engineering from the University of New South Wales. co-first author of the new study published in Science.

“Facet engineering becomes important where it is necessary to create a particular facet to improve catalytic efficiency.

“For a certain process, it may be better to have a square-shaped crystal for catalysis, or a flatter shape, and we can see from this research how we can synthesize that facet depending on the different inputs.

“It’s the same process that happens in the air with snowflakes, but now we’re able to do it with liquid metal crystals.”

Zinc crystals
Crystals of different shapes can be synthesized using a different metal solute, such as nickel (left) and bismuth (right). Credit: Dr Jianbo Tang

How This Incredibly Hot ‘Hellish Planet’ Got So Burned Up

The rocky planet 55 Cancri e (nicknamed ‘Janssen’) orbits its star so close that a ‘year’ lasts only 18 hours, which translates to a giant lava ocean for its surface and an interior that could be full of diamonds.

Janssen’s orbit has a minimum radius of around 2 million km – for comparison, Mercury, the closest planet to our sun, is 46 million km away and Earth’s is around 147 million km away .

Now, new research has shed light on how this devilishly hot exoplanet could have gotten so hot.

Using a new tool called EXPRES (Exoplanetary and Planetary Radio Emission Simulator), astronomers have captured ultra-precise measurements of slight shifts in the bright light of Janssen’s star, Copernicus.

Illustration of cancri e in front of copernicus
This artist’s impression shows super-Earth 55 Cancri e in front of its parent star. Thanks to observations made with the NASA/ESA Hubble Space Telescope and new analysis software, scientists were able to analyze the composition of its atmosphere. It was the first time this was possible for a super-Earth. 55 Cancri e is about 40 light-years away and orbits a star that is slightly smaller, cooler, and dimmer than our Sun. Because the planet is so close to its parent star, surface temperatures are thought to reach around 2000 degrees Celsius. Credit: ESA/Hubble, M. Kornmesser

Janssen orbits at the Copernican equator, but the other exoplanets have wildly different and misaligned orbital paths. Scientists believe Jannsen likely formed in a relatively cooler orbit farther out and slowly fell toward the star over time.

The study, published in natural astronomy, found that Copernicus was spinning. So the researchers propose that this caused its midsection to bulge slightly outward and that the asymmetry affected the gravity Janssen felt – causing the planet to align with the star’s thicker equator. .

New council launched to champion Australia’s biodiversity

Leading experts, including Indigenous knowledge holders, from 11 Australian universities have come together to form a new council advocating for Australia’s catastrophically declining biodiversity.

Environment and Water Minister Tanya Plibersek launched the Biodiversity Council on Wednesday, December 7, in line with the federal response to an independent review of the Environmental Protection and Conservation Act. biodiversity (EPBCA).

It will promote public, policy and industry recognition of Australia’s biodiversity crisis – highlighted in the recently released State of the Environment report – as well as the importance of biodiversity to well-being and prosperity, and positive opportunities and solutions to address its challenges. .

“There is currently no specialized biodiversity think tank providing commentary on the adequacy of current policy, bringing together expertise to support all levels of government and industry to adopt solutions, halt extinctions and reverse biodiversity loss. The Council will be Australia’s voice on biodiversity,” said Professor Hugh Possigham, Chief Adviser to the Biodiversity Council.

The Biodiversity Council will initially be hosted by the University of Melbourne and was created with contributions from six other philanthropic grantees.

It is the strongest material on Earth

Microscopy images of crconi alloy
Microscopy-generated images showing the path of a fracture and accompanying crystal structure deformation in the nanoscale CrCoNi alloy during stress testing at 20 kelvin (-253.15°C). The fracture propagates from left to right. Credit: Robert Ritchie/Berkeley Lab

Scientists have measured the strongest material on record – a metal alloy composed of chromium, cobalt and nickel (CrCoNi).

Not only is the metal extremely malleable (resistant to fracture) and incredibly strong (meaning it resists permanent deformation), but these qualities also improve as it cools, which goes to the against most other materials.

The material belongs to a subclass of metals called high entropy alloys (HEA). Basically, while all alloys used today contain a high proportion of one element and lower amounts of additional elements, HEAs are made of an equal mixture of each.

Scanning electron microscope image of metal alloys
These images, generated by scanning electron microscopy, show the grain structures and crystal lattice orientations of the (A) CrMnFeCoNi and (B) CrCoNi alloys. (C) and (D) show examples of fractures in CrCoNi at 293 kelvin and 20 kelvin, respectively. Credit: Robert Ritchie/Berkeley

The toughness of this material near the temperatures of liquid helium (20 kelvins, -253.15°C) reaches 500 megapascal square root meters. In the same units, the toughness of a piece of silicon is one, the aluminum airframe of passenger aircraft is about 35, and the toughness of some of the best steel is about 100. So 500 is is a staggering number,” the research explains. co-leader Robert Ritchie, who is a professor of engineering at the University of California at Berkeley in the United States.

The record results have been published in a new study in Science.

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