Local Ir dedimerization followed by ligand-hole hopping in X-ray irradiated thiospinel

Hiraka, Haruhiro*; Matsumura, Daiju; Horigane, Kazumasa*; Mizuki, Junichiro*

Journal of Physics and Chemistry of Solids, 150, p.109870_1 - 109870_8, 2021/03

https://doi.org/10.1016/j.jpcs.2020.109870

Antiferromagnetic order of the Co high-spin state with a large orbital angular momentum in LaCaCoO

Okamoto, Jun*; Nakao, Hironori*; Yamasaki, Yuichi*; Wadachi, Hiroki*; Tanaka, Arata*; Kubota, Masato; Horigane, Kazumasa*; Murakami, Yoichi*; Yamada, Kazuyoshi*

Journal of the Physical Society of Japan, 83(4), p.044705_1 - 044705_6, 2014/04

https://doi.org/10.7566/JPSJ.83.044705

Spin fluctuations in oxygen doped layered perovskite cobalt oxide

Nakajima, Kenji; Kajimoto, Ryoichi; Yamada, Kazuyoshi*; Horigane, Kazumasa*

no journal, , 

Carrier doping into transition metal oxides triggers various phenomena, which have been subjected to intensive investigations. Layered oxide LaMO (M: 3d metal) is one of the model systems for such studies. In cobalates, contribution of orbital moment and possible spin state of Co give further complexity. In LaSrCoO, charges order in checker-board style and Co spin correlations are modulated in momentum space by the ordered charges. (1) Magnetic excitations in this system are reported to be accounted for spin-waves of Co spins taking into account the orbital moment. (2) In this study, we have investigated magnetic excitations in another almost half-doped system LaCoO by inelastic neutron scattering. Clear spin-wave excitations consistent to previous report on LaSrCoO were observed. However, we also observed an additional excitations with different zone center positions as well as excitation with higher spin-wave velocity. We expect detail analysis of present results can provide a key clue to understand the mechanism of complicated magnetic excitations caused by doped carrier, spin-orbital coupling and spins in transition metal oxides.