In recent years, ultrahigh magnetic fields exceeding 1000 tesla have become available for experiments. Such fields were found to destabilize the crystal structure of materials, inducing the emergence of new crystal structures. However, examining these structures required X-ray irradiation analysis of diffraction patterns. Generating both ultrahigh magnetic fields and X-rays requires large-scale facility-class equipment, making it difficult to combine the two for experiments.
To address this, a research group led by Associate Professor Akihiko Ikeda of the Department of Engineering Science at the University of Electro-Communications developed PINK-02, a destructive pulsed magnetic field generator that produces ultrahigh magnetic fields in the instant of an explosion by passing a current of approximately one million amperes through a single-turn coil. With this portable device, measuring approximately 1.5 meters on each side of its cube shape and weighing 1.1 tons, they succeeded in generating a magnetic field of 110 tesla. This is approximately two million times the Earth's magnetic field.
The research group transported PINK-02 to SACLA, a domestic facility which operates the world's second most powerful X-ray free electron laser. They successfully acquired X-ray diffraction data of solid oxygen under a 110-tesla magnetic field. The results confirmed that the crystal structure of solid oxygen undergoes large anisotropic lattice deformation, reaching levels as high as 1 percent.
Studying phenomena that occur under such extreme environments reveals previously unknown properties of materials and the creation of new functional materials. In the future, Ikeda and his team plan to investigate structural changes in a variety of crystals under ultrahigh magnetic fields; they aim to reveal a completely new crystal structure in solid oxygen predicted to appear around 120 tesla.
(Article: Masanori Nakajo)
