河智 史朗

In strong magnetic fields beyond 100 T, the significant Zeeman energy competes with the lattice interactions, where a considerable magnetostriction is expected. However, the microscopic observation of the magnetostriction above 100 T has been hindered due to the short pulse duration of microseconds and the coil’s destruction. Here, we report the observation of the giant and anisotropic magnetostriction of ∼ 1 % at 110 T in the spin-controlled crystal β − O 2 by combining the single-shot diffraction of an x-ray free-electron laser (XFEL) and the newly developed portable 100 T generator (PINK-02). The soft and anisotropic response of β − O 2 should originate in the competing van der Waals force and exchange interaction and also the frustration of spin and lattice on the triangular network. The XFEL experiment above 100 T using PINK-02 enables microscopic investigations on materials’ properties at high magnetic fields, providing insights into how spins contribute to the stability of crystal structures.

We developed a resistance measurement using radio frequency reflection to investigate the electrical transport characteristics under destructive pulsed magnetic fields above 100 T. A sample stage consisting of a homemade flexible printed circuit reduced the noise caused by the induced voltage from the pulsed magnetic fields, improving the accuracy of the measurements of the reflected waves. From the obtained reflectance data, the absolute value of the magnetoresistance was successfully determined by analyzing the phase with admittance charts. These developments enable more accurate and comprehensive measurements of electrical resistance in pulsed magnetic fields.