A new spintronics border: almost antiferromagnetic revealed

The quasi-cristals (QC) are fascinating solid materials which have an intriguing atomic arrangement. Unlike regular crystals, in which atomic arrangements have an ordered repetition motif, the QC display the atomic order in long range which is not periodic. Due to this “almost” almost “nature, QC have unconventional symmetries which are absent in conventional crystals.

Since their winning discovery of the Nobel Prize, researchers in the condensed matter physics have devoted immense attention to QC, trying to both their unique almost almost almost quasiperiodic order and their possible spintronic and magnetic refrigeration applications.

Ferromagnetism has recently been discovered in Icosaédriques Icosaédriques (IQC) QC. However, scientists were not surprised by this observation because the translational periodicity – the repetitive arrangement of atoms in a crystal – is not a prerequisite for the emergence of the ferromagnetic order.

On the other hand, the other fundamental type of magnetic order found in nature, anti -proponomagnetism, is intrinsically more sensitive to crystalline symmetry.

Although theorists have long expected to establish the creation of antiferromagnetism in certain QCs, it has not yet been observed. Experimentally, most magnetic IQCs have a spin -verre freezing behavior, without any long -term magnetic sign, which has led researchers to wonder if anti -fetches is even compatible with quasipedicality – until now.

In a revolutionary study, a research team finally discovered anti -feturomagnetism in a real QC. The team was led by Ryuji Tamura of the Department of Science and Technology of Materials at the University of Sciences of Tokyo (TUS), as well as Takaki Abe, also of Tus, Taku J. Sato of Tohoku University, and Max Avdeev of the Australian Organization of Nuclear Sciences and Technology and the University of Sydney.

Their study is published in the journal Nature physics.

“As was the case for the first report of antiferromagnetism in a periodic crystal in 1949, we present the first experimental proofs of anti -proponomagnetism occurring in an IQC,” explains Tamura.

Based on their recent discovery of ferromagnetism in the IQC Au-Ga-R, the researchers identified a new IQC of the Or-Indium-European type (Au-É-EU), with rotational symmetries five times, three and twice. The team carried out a series of loose property and neutron experiences to examine its magnetic nature.

Magnetic sensitivity measurements have shown a sharp cusp at a temperature of 6.5 Kelvin (K) for the conditions cooled and cooled by the zero field, in accordance with an antiferromagnetic transition. Specific heat measurements have also shown a peak at the same temperature, checking that the CUSP is due to a long -range magnetic order.

To Further Validate Their Results, The Team Performed Neutron Diffraction Measurements of the IQC at Temperatures of 10 K and 3 K. They observed Additional Magnetic Bragg Peaks – Sharp Intensity Peaks in the Diffraction Pattern Indicating An Ordered Magnetic Structure – Which Consistantly Showed Around the Transition Temperature of 6.5 K in Temperature Dependent Measurements, Providing the First Clear Evidence of Long-Foreign Antiferromagnetic Order in a real QC.

As for the reason why the IQC Au-IU hosts an antiferromagnetic phase, researchers have found that, unlike the previously studied IQCs, which generally have a negative temperature of Curie-Weiss, this new IQC has a positive curia temperature.

Interestingly, they also discovered that with a slight increase in the electronic ratio by atom by elementary substitution, the anti -Ferromagnetic phase disappears and the IQC shows a spin glass behavior, a bit like the previous IQCs.

This suggests that the IQCs with a positive temperature of Curie-Weiss promote the establishment of the antiferromagnetic order, opening up new avenues for future studies to develop new antiferromagnetic QCs by controlling the electronic ratio by atom.

“Finally, this discovery resolves the long -standing question whether the antiferromagnetic order is possible in real QCs,” adds Tamura. “Antiferromagnetic QC could allow unprecedented functions, such as ultrasoft magnetic responses, and will cause a spintronic revolution and magnetic refrigeration in the future.”

The discovery of researchers alignments with the United Nations Sustainable Development Goals (SDGs) – Affordable and Clean Energy (ODD 7), industry, innovation and infrastructure (ODD 9) – by energy economical in energy.

Resolving a mystery of several decades, this discovery not only invigorates the search for unexplored antiferromagnetic QC, but also opens up a new area of ​​search for almost anti-Ferromagnets, with implications extending far beyond the spintronics.