Emergence of novel phase of solid oxygen in ultrahigh magnetic Held

27th International Conference on Low Temperature Physics

Kobayashi, T.C.^1 ; Nomura, T.^2 ; Matsuda, Y.H.^2 ; Her, J.L.^3 ; Takeyama, S.^2 ; Matsuo, A.^2 ; Kindo, K.^2

Department of Physics, Okayama University, Okayama

700-8530, Japan^1

Institute for Solid State Physics, University of Tokyo, Kashiwa, 277-8581, Japan^2

Chang Gung University, Kwei-Shan, Tao-Yuan

333, Taiwan^3

关键词: Antiferromagnetic phase;    Cohesive energies;    First order transitions;    Magnetic energies;    Magnetic-field-induced phase transitions;    Molecular geometries;    Ultra-high magnetic fields;    Visible light absorption;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/568/4/042018/pdf
DOI  :  10.1088/1742-6596/568/4/042018

来源: IOP

【 摘 要 】

Faraday discovered the magnetism of molecular oxygen in 1850, and since then, oxygen has attracted significant interests as a ubiquitous but exotic molecular magnet. In solid oxygen, the magnetic energy through the exchange interaction is comparable to the van der Waals cohesive energy, resulting in a strong spin-lattice correlation. We reported the discovery of a magnetic-field-induced phase transition of solid oxygen using ultrahigh magnetic fields up to 186 T. This is the first experiments demonstrating the phase control through the spin by applying a magnetic field. Magneto-optical absorption measurements of the α phase at low temperatures revealed that visible light absorption suddenly ceases and the background transparency dramatically improves above the critical field. The large hysteresis in these data indicates a first-order transition with a relaxation time on the order of microseconds. The results strongly suggest the reconstruction of the O2molecular geometry by the magnetic field, which causes that the antiferromagnetic phase collapses and the field-induced phase should have an isotropic crystal structure. Since all of the known phases of O2are induced in high pressure, the discovery of a field-induced phase is noteworthy in the long history of solid O2studies.