New ordered state in transuranium oxide NpO2


  We grew high quality single crystals of NpO2, and clarified the new ordered state due to the magnetic octupolar by the nuclear magnetic resonance (NMR) measurements. The magnetic octupole order is related with the anisotropic distribution of the magnetic moment, which is induced by the quantum behavior of spin and orbital. This is "spontaneous symmetry breaking", which is universally observed as a physical phenomenon. High quality single crystals and microscopic experiments put an end to the half century mystery. This result was published in Phys. Rev. Lett., and was reported in "Kahoku Shimpo" and "Nikkan Kogyo Shimbun" on Dec. 20, 2006, as well. The work has been done in collaboration with Japan Atomic Energy Agency.
High quality single crystal of NpO2 grown  by the chemical transport method

High quality single crystal of NpO2 grown by the chemical transport method

Prof. Shiokawa’s group (Radiochemistry of Metals),
International Research Center for Nuclear Materials Science