Recent research has revealed a surprising link between the behavior of electrons and the physical structure of solid oxygen when subjected to extraordinarily powerful magnetic fields. Scientists have demonstrated that these intense magnetic forces can significantly alter the arrangement of atoms within the solid, leading to a distortion of its crystalline structure.
Extreme Magnetic Fields: A Realm of New Phenomena
Placing materials under extremely strong magnetic fields – far beyond anything typically encountered in everyday life – often gives rise to unusual and fascinating physical changes. When magnetic fields surpass 100 tesla (T), the intrinsic magnetic orientations of electrons, known as spins, and the atoms themselves begin to organize in new ways, potentially leading to the emergence of new phases of matter or the stretching of a crystal lattice.
One key phenomenon observed under these conditions is magnetostriction, where a material’s crystal structure undergoes deformation—stretching, shrinking, or twisting—in response to the magnetic field.
The Challenge of Generating Intense Magnetic Fields
Producing such powerful magnetic fields poses a significant engineering challenge. Current technology allows these fields to be maintained only for extremely short durations, typically just a few microseconds. This is because the intense forces involved place tremendous stress on the coils used to generate the fields, often causing them to break down almost immediately.
A Breakthrough in Magnetic Field Generation
Researchers at the University of Electro-Communications in Tokyo, RIKEN, and other institutions in Japan have recently made a crucial advancement in this field. They have developed novel equipment capable of briefly generating magnetic fields around 110 T and simultaneously capturing the positions of atoms within a material exposed to these fields.
Their findings, recently published in Physical Review Letters, provide new insights into the behavior of solid oxygen under these extreme conditions. “The primary goal of this study was to explore the extreme world of ultrahigh magnetic fields between 100 and 1,000 T,” explained Akihiko Ikeda, the study’s first author, in an interview with Phys.org. “Our experiment, which involved applying a field above 100 T for the first time, represents a significant step forward in this area of research.”
Capturing Atomic Snapshots Under Pressure
To achieve this, Ikeda and his team utilized a newly developed portable magnetic field generator, dubbed PINK-02, which allowed them to create an exceptionally strong magnetic field of approximately 110 T for a few brief microseconds. They then combined this with laser technology to emit ultrafast XFEL X-ray pulses at solid oxygen crystals while they were exposed to the intense magnetic field. This allowed them to effectively capture “snapshots” revealing the precise positions of the oxygen atoms during the magnetic pulse.
“The novelty of our work lies in the newly designed portable 100 T generator, PINK-02, which is absolutely essential for these types of studies,” explained Ikeda. “Its portability made it possible to combine it with the X-ray free-electron laser.”
A Giant Stretch: Magnetostriction in Solid Oxygen
By meticulously analyzing these snapshots and comparing the atomic positions before and during the magnetic field exposure, the researchers uncovered remarkable results. They observed a significant magnetostriction in the solid oxygen, where the crystal structure was stretched by approximately 1%. This indicates a substantial alteration in the material’s physical arrangement under the influence of the intense magnetic field.
The team’s observations suggest a complex interplay between electron spins and the forces governing the crystal lattice. Under magnetic fields exceeding 100 T, electron spins exert a considerable influence on the crystal structure of solid materials, particularly in the case of solid oxygen.
Future Directions in Condensed Matter Physics
The magnetic field generator and X-ray laser technology developed by the team offer promising opportunities for exploring other materials under similarly extreme conditions.
“Our findings demonstrate that electron spins can affect the stability of a material’s crystal structure, as we’re seeing with solid oxygen,” added Ikeda. “We plan to increase the available magnetic fields up to 120 to 130 T to further investigate the structure of a specific solid oxygen phase called the θ phase. We also aim to uncover structural changes in various materials above 100 T.”
In conclusion, this research demonstrates the powerful influence of electron spins on the crystalline structure of solid materials under extreme magnetic fields. The development of portable, high-field generators and advanced X-ray techniques opens exciting new avenues for exploring the fundamental properties of matter at its limits.
