Anomalous metallic state in the vicinity of metal to valence-bond solid insulator transition in LiVS

Katayama, Naoyuki*; Uchida, Masaya*; Hashizume, Daisuke*; Niitaka, Seiji*; Matsuno, Jobu*; Matsumura, Daiju; Nishihata, Yasuo; Mizuki, Junichiro; Takeshita, Nao*; Gauzzi, A.*; et al.

Physical Review Letters, 103(14), p.146405_1 - 146405_4, 2009/10

https://doi.org/10.1103/PhysRevLett.103.146405

We investigate LiVS and LiVSe with a triangular lattice as itinerant analogues of LiVO known for the formation of a valence-bond solid (VBS) state out of an S = 1 frustrated magnet. LiVS, which is located at the border between a metal and a correlated insulator, shows a first order transition from a paramagnetic metal to a VBS insulator at T 305 K upon cooling. The presence of a VBS state in the close vicinity of insulator-metal transition may suggest the importance of itinerancy in the formation of a VBS state. We argue that the high temperature metallic phase of LiVS has a pseudogap, likely originating from the VBS fluctuation. LiVSe was found to be a paramagnetic metal down to 2 K.

New cross-over project study, 7; Study on swift heavy ion-irradiation effects of simulation material of nuclear fuel "CeO" by means of synchrotron radiation

Ono, Hirotaka*; Maeda, Nobuhiro*; Nakagawa, Sho*; Zushi, Yoshihiro*; Iwase, Akihiro*; Baba, Yuji; Hirao, Norie*; Ishikawa, Norito; Chimi, Yasuhiro; Sataka, Masao; et al.

no journal, , 

X-ray absorption spectroscopy is applied for evaluation of heavy ion irradiation effects in sim-fuel CeO in order to investigate the radiation damage of nuclear fuels bombarded by fission fragments. It is found that oxygen atoms are displaced via elastic displacement process, and the charge state of Ce changes from 4+ to 3+.

Theory of single molecule imaging by X-ray free-electron laser

Tokuhisa, Atsushi; Taka, Junichiro; Kono, Hidetoshi; Go, Nobuhiro*

no journal, ,