Paidi Vinod K, Lee Byoung-Hoon, Lee Alex Taekyung, Ismail-Beigi Sohrab, Grishaeva Elizaveta, Vasala Sami, Glatzel Pieter, Ko Wonjae, Ahn Docheon, Hyeon Taeghwan, Kim Younghak, Lee Kug-Seung
Experiments Division, European Synchrotron Radiation Facility, Grenoble 38043, Cedex 9, France.
Graduate School of Converging Science and Technology, Korea Universy - Korea Institute of Science and Technology, Seoul 028041, Republic of Korea.
Proc Natl Acad Sci U S A. 2024 Nov 26;121(48):e2409397121. doi: 10.1073/pnas.2409397121. Epub 2024 Nov 18.
Oxygen vacancies and their correlation with the nanomagnetism and electronic structure are crucial for applications in dilute magnetic semiconductors design applications. Here, we report on cobalt single atom-incorporated titanium dioxide (TiO) monodispersed nanoparticles synthesized using a thermodynamic redistribution strategy. Using advanced synchrotron-based X-ray techniques and simulations, we find trivalent titanium is absent, indicating trivalent cations do not influence ferromagnetic (FM) stability. Density functional theory calculations show that the FM stability between Co ions is very weak. However, electron doping from additional oxygen vacancies can significantly enhance this FM stability, which explains the observed room-temperature ferromagnetism. Moreover, our calculations illustrate enhanced FM interactions between Co + V complexes with additional oxygen vacancies. This study explores the electronic structure and room-temperature ferromagnetism using monodispersed nanocrystallites with single-atom-incorporated TiO nanostructures. The strategies described herein offer promise in revealing magnetism in other single-atom-incorporated nanostructures.
氧空位及其与纳米磁性和电子结构的相关性对于稀磁半导体设计应用至关重要。在此，我们报告了使用热力学再分布策略合成的钴单原子掺杂二氧化钛（TiO）单分散纳米颗粒。利用先进的基于同步加速器的X射线技术和模拟，我们发现不存在三价钛，这表明三价阳离子不会影响铁磁（FM）稳定性。密度泛函理论计算表明，Co离子之间的FM稳定性非常弱。然而，额外氧空位的电子掺杂可以显著增强这种FM稳定性，这解释了所观察到的室温铁磁性。此外，我们的计算表明，具有额外氧空位的Co + V络合物之间的FM相互作用增强。本研究使用单原子掺杂TiO纳米结构的单分散纳米微晶探索了电子结构和室温铁磁性。本文所述的策略有望揭示其他单原子掺杂纳米结构中的磁性。
