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Electron energy‐loss spectroscopy (EELS) is widely applied combining with transmission electron microscopes with high spatial resolution, but its interpretation is a challenging task. One of the reasons is that the factors affecting EELS are very complicated. In this paper, we focus on the several factors involved in density functional theory (DFT) calculations. The sensitivity of calculated energy‐loss near‐edge structure (ELNES) to spin order, pressure and on‐site Coulomb energy U has been discussed. Since EELS technique detects the local environment of atoms, the influence of spin order cannot be ignored. The chemical shifts and peak intensity of ELNES are also closely related to corresponding pressure. The correlation effects are very important for transition metal compounds and play a key role in EELS simulations. An overview of the effects of these factors on the ELNES is presented with the help of Wien2k code. The antiferromagnetic order results in the decreasing of intensities of related peaks and the moving of the peaks to high energy loss. The decreasing of lattice parameters causes the ELNES peaks to shift to high energy loss, and the peak shifts at the higher energy loss are more significant. The increase of correlation effect leads to the ELNES peaks to shift to high energy loss accompanied by the increase of the relative intensity of the peaks which locate at higher energy loss. Our work helps to understand how these factors affect EELS and to explain and predict the experimental EELS spectra. Through the discussion of these factors, we propose that some factors could not be ignored in EELS simulations. Lay description: Transmission electron microscope (TEM) is a powerful scientific instrument, which can be used for small size imaging. In recent decades, it has helped scientists to make important discoveries such as carbon nanotube and quasicrystal and has been widely used in materials science, condensed matter physics, structural biology and other fields. The principle of transmission electron microscope is similar to that of optical microscope, but its resolution is far superior to that of optical microscope. Compared with the resolution of optical microscope about 300 nm, the resolution of transmission electron microscope can reach 0.039 nm at present. In addition to excellent spatial resolution, transmission electron microscope has many functions such as structural analysis, elemental composition analysis and electronic structure analysis. TEM can be also used to carry out in situ observation and time resolution observation. Because of its several advantages mentioned above, transmission electron microscopy attracts much attention since its birth in the early 1930s. The early TEM was considered to be used only to magnify the observed object, but the electron energy‐loss spectroscopy (EELS) gives it the ability to determine the composition of the sample and analyse the electronic structure. EELS is widely applied combining with transmission electron microscopes with high spatial resolution, but its interpretation is a challenging task. One of the reasons is that the factors affecting EELS are very complicated. In this paper, we focus on several factors involved in density functional theory calculations. The sensitivity of calculated energy‐loss near‐edge structure to spin order, lattice compression and expansion, and on‐site Coulomb energy is discussed. Since EELS technique detects the local environment of atoms, the influence of spin order cannot be ignored. The chemical shift and peak intensity of EELS are also closely related to corresponding lattice parameters. The correlation effects are very important for transition metal compounds and play a key role in EELS simulations. Our work helps to understand how these factors affect EELS and to explain and predict the experimental EELS spectra. Through the discussion on these factors, we provide a useful guidance for more precise EELS simulations. [ABSTRACT FROM AUTHOR]

The effect of antisite defects and their density on monolayer hexagonal boron nitride is discussed in detail. Different supercell sizes to simulate different defect densities are set up. All structures containing antisites are fully optimized. It is indicated that the high density of antisite defects leads to the instability of the BB bond. The influence of supercell size on lattice structure is also summarized. Like vacancies and dopant atoms, the antisite defects also lead to the appearance of the defect energy band. Different antisite defect densities have different effects on different orbitals. Electron energy‐loss spectroscopy theoretical simulation is conducted on a single atom to analyze the influence of antisite defect density on the electronic structure of a single atom. It is shown that the high density of antisite defects makes the σ* transition of B atoms that are far away from the defect more preferred than π* transition, while it has less influence on the transition of central N atoms of the antisite defect NB because of the influence of neighboring atoms. The concentration of antisite defects plays a key role in manipulating the physical properties of monolayer hexagonal boron nitride and is helpful in expanding potential application scenarios. [ABSTRACT FROM AUTHOR]

• Good epitaxial growth among substrate, Cr 2 O 3 interlayer and crystalline CrO 2 film. • There is a higher oxygen concentration between the Cr 2 O 3 film and substrate. • The Cr 2 O 3 interlayer may be inevitable for generating CrO 2. Epitaxial chromium dioxide (CrO 2) film was grown on sapphire Al 2 O 3 by the chemical vapor deposition (CVD) method. The interfacial structure of the epitaxial CrO 2 was characterized by transmission electron microscopy (TEM), and the spatial distribution of the chromium valence in the film was qualitatively analyzed by electron energy loss spectroscopy (EELS). An uneven transition layer with a diffraction pattern consistent with that of Cr 2 O 3 but with an anomalously large oxygen concentration (Cr/O ≈ 0.2–0.3) was found between the CrO 2 film and the substrate. [ABSTRACT FROM AUTHOR]

• SCO-LSMO bilayer films are fabricated by PLD technique. • SCO has been defined to be Ima 2 structure. • Domains and stack-fault structures are detected in SCO layer. • A peculiar nanocrystalline embeds in the SCO-LSMO interface. SrCoO 3-δ (0 < δ < 0.5) film has shown great potential in applications for interface engineering of spintronic devices due to its multiformity of crystal structures and magnetic properties. In this work, we have studied the microstructures of SrCoO 3-δ in SrCoO 2.5 -La 0.67 Sr 0.33 MnO 3 (SCO-LSMO) double-layered films by using scanning transmission electron microscopy. Our fabricated SCO film is determined to have a structure with the Ima 2 space group (No. 46). Perpendicular domain and stack-fault structures are observed to coexist in the SCO layer. In the joint of domains, oxygen content remains a constant for octahedra layers but a slight rise for tetrahedra layers. Continuous changes of oxygen content are also detected in the same level layer in the stack-fault region near the domain boundary. Besides, a peculiar nanocrystalline is observed at the interface of SCO-LSMO. The electron energy-loss spectroscopy results show that the Co ions in nanocrystalline have a lower valence, indicating a chemical compositon of SrCoO 2.5-δ (0 < δ < 0.5). [ABSTRACT FROM AUTHOR]

Li‐rich layered metal oxides are one type of the most promising cathode materials in lithium‐ion batteries but suffer from severe voltage decay during cycling because of the continuous transition metal (TM) migration into the Li layers. A Li‐rich layered metal oxide Li1.2Ti0.26Ni0.18Co0.18Mn0.18O2 (LTR) is hereby designed, in which some of the Ti4+ cations are intrinsically present in the Li layers. The native Li–Ti cation mixing structure enhances the tolerance for structural distortion and inhibits the migration of the TM ions in the TMO2 slabs during (de)lithiation. Consequently, LTR exhibits a remarkable cycling stability of 97% capacity retention after 182 cycles, and the average discharge potential drops only 90 mV in 100 cycles. In‐depth studies by electron energy loss spectroscopy and aberration‐corrected scanning transmission electron microscopy demonstrate the Li–Ti mixing structure. The charge compensation mechanism is uncovered with X‐ray absorption spectroscopy and explained with the density function theory calculations. These results show the superiority of introducing transition metal ions into the Li layers in reinforcing the structural stability of the Li‐rich layered metal oxides. These findings shed light on a possible path to the development of Li‐rich materials with better potential retention and a longer lifespan. [ABSTRACT FROM AUTHOR]