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Effect of non-metallic X(X=F, N, S) and Cr co-doping on properties of BiFeO3: A first-principles study
摘要: In this study, the structural, magnetic, electric and optical properties in X (X=F, N, S) and Cr co-doped BiFeO3 (BFO) are calculated using the density functional theory. For Cr–X co-doping case, the structure of BFO undergo a phase transition from monoclinic to triclinic structure accompanying net magnetic moments of 5.92 μB, 6.04 μB and 7.80 μB, for Cr–F co-doping, Cr–N co-doping and Cr–S co-doping, respectively. The underlying physical mechanisms are the lattice distortions tunned by doping. The decreased Fe–O–Fe bond angles and Fe–O bond lengths will bring weak antiferromagnetism superexchange interaction. In addition, the band gaps of Cr–X co-doping cases are decreased from 2.20 eV (BFO bulk) to 1.31 eV and 1.80 eV for Cr–F co-doping and Cr–S co-doping, respectively, which are well for photovoltaic applications according to the well-known Shockley-Queisser criterion, suggesting a possible great improvement optical properties in Cr–X co-doped samples.
关键词: Lattice distortion,Optical properties,Non-metal and transition-metal co-doped BiFeO3,Magnetic moments
更新于2025-09-23 15:21:01
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[Advances In Atomic, Molecular, and Optical Physics] Volume 67 || Zeeman Spectroscopy in Penning Traps
摘要: Penning traps are the instruments of choice to determine the magnetic moments of long lived or stable charged particles. The virtual absence of collisions with background molecules when working in ultra-high vacuum, the small volume which the trapped particles occupy at low kinetic energies, and the extremely long observation and coherence times allow for very high precision in Zeeman spectroscopy. When applied to singly ionized multielectron atoms the experiments serve for tests of atomic structure calculations. The magnetic moments in few-electron systems such as hydrogen- or lithium-like highly charged ions can be calculated with remarkable precision in the frame of bound-state quantum electrodynamics. The results not only test corresponding calculations but also have impact on fundamental particle properties and fundamental constants. The chapter summarizes results obtained in recent years on various low- and highly charged systems.
关键词: magnetic moments,Penning traps,fundamental constants,quantum electrodynamics,Zeeman spectroscopy
更新于2025-09-10 09:29:36