2023/09/07 by Nam Nguyen, Alex Taekyung Lee, Nguyen, Nam +7
Materials Science · #Magnetic and transport properties of perovskites and related materials #Iron-based superconductors research #Multiferroics and related materials
paper · pdf · doi:10.48550/arxiv.2309.03995
La doped SrFeO3, La1/3Sr2/3FeO3, exhibits a metal-to-insulator transition accompanied by both antiferromagnetic and charge ordering states along with the Fe-O bond disproportionation below a critical temperature near 200K. Unconventionally slow charge dynamics measured in this material near the critical temperature shows that its excited charge ordering states can exhibit novel electronic structures with nontrivial energy profiles. Here, we reveal possible metastable states of charge ordering structures in La1/3Sr2/3FeO3 using the first-principle and climbing image nudged elastic band methods. In the strong correlation regime, La1/3Sr2/3FeO3 is an antiferromagnetic insulator with a charge ordering state of the big-small-big pattern, consistent with the experimental measurement of this material at the low temperature. As the correlation effect becomes weak, we find at least two possible metastable charge ordering states with the distinct Fe-O bond disproportionation. Remarkably, a ferroelectric metallic state emerges with the small energy barrier of ∼7 meV, driven by a metastable CO state of the small-medium-big pattern. The electronic structures of these metastable charge ordering states are noticeably different from those of the ground-state. Our results can provide an insightful explanation to multiple metastable charge ordering states and the slow charge dynamics of this and related oxide materials.