Spin-charge coupling and decoupling in perovskite-type iron oxides (Sr1−xBax)2/3La1/3FeO3

作     者：M. Onose H. Takahashi T. Saito T. Kamiyama R. Takahashi H. Wadati S. Kitao M. Seto H. Sagayama Y. Yamasaki T. Sato F. Kagawa S. Ishiwata 

作者机构：Department of Applied Physics University of Tokyo Bunkyo-ku Tokyo 113-8656 Japan Division of Materials Physics and Center for Spintronics Research Network (CSRN) Graduate School of Engineering Science Osaka University Toyonaka Osaka 560-8531 Japan Division of Spintronics Research Network Institute for Open and Transdisciplinary Research Initiatives Osaka University Yamadaoka 2-1 Suita Osaka 565-0871 Japan Institute of Materials Structure Science (IMSS) High Energy Accelerator Research Organization (KEK) Tokai Ibaraki 319-1106 Japan The Graduate University for Advanced Studies SOKENDAI Tokai Ibaraki 319-1106 Japan Department of Material Science Graduate School of Science University of Hyogo Ako Hyogo 678-1297 Japan Institute of Laser Engineering Osaka University Suita Osaka 565-0871 Japan Institute for Integrated Radiation and Nuclear Science Kyoto University Kumatori Osaka 590-0494 Japan Institute of Materials Structure Science (IMSS) High Energy Accelerator Research Organization (KEK) Tsukuba Ibaraki 305-0801 Japan National Institute for Materials Science (NIMS) Tsukuba Ibaraki 305-0047 Japan RIKEN Center for Emergent Matter Science (CEMS) Wako Saitama 351-0198 Japan Research Center of Integrative Molecular Systems (CIMoS) Institute for Molecular Science Myodaiji Okazaki 444-8585 Japan The Graduate University for Advanced Studies SOKENDAI Myodaiji Okazaki 444-8585 Japan 

出 版 物：《Physical Review Materials》 (Physic. Rev. Mat.)

年 卷 期：2022年第6卷第9期

页      面：094401-094401页

核心收录：

基　　金：Asahi Glass Foundation, AGF Japan Society for the Promotion of Science, KAKEN, (19H05824, 19K14652, 20H01866, 21H01030, 22H00343, 22J13408) Murata Science Foundation 

主　　题：Charge order Magnetic order Phase diagrams Perovskites Strongly correlated systems Transition metal oxides 

摘      要：The perovskite-type iron oxide Sr2/3La1/3FeO3 is known to show characteristic spin-charge ordering (SCO), where sixfold collinear spin ordering and threefold charge ordering are coupled with each other. Here, we report the discovery of a spin-charge decoupling and an antiferromagnetic (AFM) state competing with the SCO phase in perovskites (Sr1−xBax)2/3La1/3FeO3. By comprehensive measurements including neutron diffraction, Mössbauer spectroscopy, and x-ray absorption spectroscopy, we found that the isovalent Ba2+ substitution systematically reduces the critical temperature of the SCO phase and additionally yields the spin-charge decoupling in x0.75. Whereas the ground state remains in the SCO phase in the whole x region, an unexpected G-type AFM phase with incoherent charge ordering or charge fluctuation appears as the high-temperature phase in the range of x0.75. Reflecting the competing nature between them, the G-type AFM phase partially exists as a metastable state in the SCO phase at low temperatures. We discuss the origin of the spin-charge decoupling and the emergence of the G-type AFM phase with charge fluctuation in terms of the bandwidth reduction by the Ba substitution.