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Magnetic frustration in atacamite triggers dramatic cooling when exposed to strong fields

Natural crystals fascinate with their vibrant colors, their nearly flawless appearance and their manifold symmetrical forms. But researchers are interested in them for quite different reasons: Among the countless minerals already known, they always discover some materials with unusual magnetic properties.

One of these is atacamite, which exhibits magnetocaloric behavior at low temperatures—that is, the material’s temperature changes significantly when it is subjected to a . A team headed by TU Braunschweig and the HZDR has now investigated this rare property. In the long term, the results, now published in Physical Review Letters, could help to develop new materials for energy-efficient magnetic cooling.

The emerald-green mineral atacamite, named for the place it was first found, the Atacama Desert in Chile, gets its characteristic coloring from the copper ions it contains. These ions also determine the material’s magnetic properties: they each have an unpaired electron whose spin gives the ion a —comparable to a tiny needle on a compass.

Wafer lens changes X-ray beam size by more than 3,400 times

Using only a single-crystal piezoelectric thin wafer of lithium niobate (LN) instead of the usual two-part structure, a group from Nagoya University in Japan has created a deformable mirror that changes X-ray beam size by more than 3,400 times. This improved tuning range enhances both imaging and analysis, especially for the X-rays used in industry.

Their technique is based on LN, a material that has piezoelectricity, meaning that it changes its surface shape in response to voltage. Traditional X-ray mirrors are rigid and resistant to being deformed, making it difficult to adapt them to changing experimental conditions in real time, but the new technique can significantly change size, making it useful for a range of situations encountered in industry.

The study is published in the journal Scientific Reports.

Researchers demonstrate giant photonic isolation and gyration

The original goal of the study was to get this asymmetry to a point of perfect isolation—that is, where there is zero interaction in one direction. They successfully achieved this goal by demonstrating a giant optical isolation effect, where the propagation of light in one direction was a million times easier than in the opposite direction.

But while exploring their test devices, the engineers encountered a surprise. Their approach was so efficient that they could even get past the isolation point to where the sign of the coupling simply flipped and the phase became direction dependent. This was something that had not been seen before in time modulated coupling and is an easy path to photonic gyration.

Going forward, the Illinois researchers will work to expand their findings. They are working with their partners specializing in condensed matter to explore how longer and more elaborate chains of resonators with this kind of tunable couplings could answer fundamental questions on topological physics. Simultaneously, from an engineering standpoint, they aim to create a pure gyrator which is a universal building block of many nonreciprocal devices.

Physicists Unravel Mystery of Mercury’s Bizarre Nuclear Fission

A five-dimensional model has successfully predicted the asymmetric fission of mercury isotopes, offering new insights into nuclear fission processes beyond the well-studied elements uranium and plutonium. A five-dimensional (5D) Langevin model developed by an international team of researchers, in

Star-Shredding Spectacle: NASA Reveals Brightest Black Hole Blasts Since the Big Bang

Supermassive black holes usually lurk unseen, but when an unlucky star drifts too close they ignite titanic outbursts brighter than 100 supernovae. By mixing NASA, ESA, and ground-based data, astronomers caught three of these rare “extreme nuclear transients,” including the cheekily named “Barbie

GIFTEDCROOK Malware Evolves: From Browser Stealer to Intelligence-Gathering Tool

The threat actor behind the GIFTEDCROOK malware has made significant updates to turn the malicious program from a basic browser data stealer to a potent intelligence-gathering tool.

“Recent campaigns in June 2025 demonstrate GIFTEDCROOK’s enhanced ability to exfiltrate a broad range of sensitive documents from the devices of targeted individuals, including potentially proprietary files and browser secrets,” Arctic Wolf Labs said in a report published this week.

“This shift in functionality, combined with the content of its phishing lures, […] suggests a strategic focus on intelligence gathering from Ukrainian governmental and military entities.”

Muscle in Space Sheds Light on Ageing-Related Muscle Loss

Sarcopenia, which is a progressive and extensive decline in muscle mass and strength, is common with aging and estimated to affect up to 50% of people aged 80 and older. It can lead to disability and injuries from falls and is associated with a lower quality of life and an increased mortality. Apart from lifestyle changes, there is no current clinical treatment for sarcopenia.

Space flight with the associated absence of gravity and limited strain on muscles causes muscle weakness, a prominent feature of sarcopenia, within a short period of time, providing a time lapse view on age-related atrophy-associated changes in the muscle. This relatively short window of time in space provides a microgravity model for muscular aging and opens opportunities for studying sarcopenia, which normally takes decades to develop in patients on earth.

To understand the changes of muscle in microgravity, Siobhan Malany, Maddalena Parafati, and their team from the University of Florida, USA, engineered skeletal muscle microtissues from donor biopsies and launched them to the International Space Station (ISS) aboard SpaceX CRS-25. Their findings were published today in Stem Cell Reports. The microtissues were taken from both young, active donors and from aged, sedentary donors and cultured in an automated mini lab, which besides regular feeding and monitoring of cultures also enabled electrical stimulation to simulate exercise. On earth, the contraction strength of microtissues from young, active individuals was almost twice as much as the strength of tissues from older, sedentary individuals. After only two weeks in space, muscle strength trended to decline in the young tissues and was now more comparable to the strength of old tissues. A similar trend was seen for the muscle protein content, which was higher in young microtissues on earth compared to old microtissues but decreased in microgravity to levels measured in old tissues. Further, space flight changed gene expression, particularly in the younger microtissues and disturbed cellular processes related to normal muscle function. Interestingly, electrical stimulation could mitigate these changes in gene expression to some extent.