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Due to the potential applications in next‐generation micro/nano electronic devices and functional materials, magnetic germanium (Ge)‐based clusters are receiving increasing attention. In this work, we reported the structures, electronic and magnetic properties of CrMnGen with sizes n = 3–20. Transition metals (TMs) of Cr and Mn tend to stay together and be surrounded by Ge atoms. Small sized clusters with n ≤ 8 prefer to adopt bipyramid‐based structures as the motifs with the excess Ge atoms absorbed on the surface. Starting from n = 9, the structure with one TM atom interior appears and persists until n = 16, and for larger sizes n = 17–20, the two TM atoms are full‐encapsulated by Ge atoms to form endohedral structures. The Hirshfeld population analyses show that Cr atom always acts as the electron donor, while Mn atom is always the acceptor except for sizes 3 and 6. The average binding energies of these clusters increase with cluster size n, sharing a very similar trend as that of CrMnSin (n = 4–20) clusters, which indicates that it is favorable to form large‐sized clusters. CrMnGen (n = 6, 13, 16, 19, and 20) clusters prefer to exhibit ferromagnetic Cr–Mn coupling, while the remaining clusters are ferrimagnetic. [ABSTRACT FROM AUTHOR]

Reactive oxygen species (ROS), as one kind of the most highly oxidizing oxidants, are difficult to generate and utilize in the natural light conditions, since many materials require external strong stimuli for ROS release to be effective as pollutant degradation or biocide. In this work, we surprisingly found the ROS generation on MIL‐100(Fe)/TiO2 driven by mild natural light. Then ROS generation patterns and mechanism was revealed by chemiluminescence (CL) and density functional theory (DFT). Meanwhile, rhodamine B (RhB) can also be removed by MIL‐100(Fe)/TiO2 under natural light, which further evidence the ROS generation under the natural light. This work provides a new direction for spontaneously generating ROS releasing without external strong stimuli and has the broad potential applications in the field of pollutant degradation or antimicrobials under natural conditions. [ABSTRACT FROM AUTHOR]

The performance of aluminum alloys can be affected by the element of magnesium. Therefore, it is necessary to realize fast and accurate quantitative analysis of magnesium in aluminum alloys. Herein, high repetition rate spark discharge assisted laser-induced breakdown spectroscopy based on microchip lasers (HRR SD-LIBS) was applied to quantitatively analyze magnesium elements in aluminum alloys. Baseline correction was performed using the moving median method to obtain the net spectral data. Multivariate calibration models such as back-propagation neural network (BP), support vector machine (SVM), and random forest (RF) were established, respectively. Compared with the conventional univariate calibration model, the correlation coefficients (RP²) of BP,SVM and RF models increased from 0. 810 to 0.985, 0.997 and 0.994, while the root mean square error (RMSEP) decreased from 0.283 to 0.059 8, 0.041 0 and 0.054 2, the average relative error decreased from 26.62% to 3.13%, 2.82%, and 3.61%. It indicated that machine earning combined microchip laser-based HRR SD-LIBS significantly improved the quantitative analysis ability of LIBS. In conclusion, it is promising to achieve portable, fast, and accurate quantitative elemental analysis of alloy sample and other materials. [ABSTRACT FROM AUTHOR]

Herein, the structural evolution, electronic and magnetic properties of CrSin−/0 for n = 19–25 have been investigated at density functional theory (DFT) level. The global minimum structures of these clusters have been fully searched through a self-developed genetic algorithm code combined with DFT calculations. Both of anionic and neutral CrSin for n = 19–25 share the same configurations. All these clusters prefer to adopt endohedral structures (Cr@Si14 for sizes n = 19–21, and Cr@Si13 for larger ones) as the structural motif with the remaining Si atoms attached on the surface. Among all these clusters, CrSi22 and CrSi23 are the most prominent through the analysis of HOMO − LUMO gaps, average binding energies, and the second order of energy differences. All of these medium-sized cluster anions possess the same total magnetic moment of 1 μB, but with very different contributions from that of small sizes (n ≤ 18), except for size 22. [ABSTRACT FROM AUTHOR]

Herein, the structural evolution, electronic and magnetic properties of silicon clusters with two different dopants, CrMnSin (n = 4–20) clusters were investigated at density functional theory (DFT) level. Small‐sized CrMnSin (n = 4–9) clusters tend to adopt bipyramid‐based geometries, while clusters with sizes n = 10 and 11 prefer to opening cage‐like structures. For sizes n = 12 to 14, the half‐encapsulated structures gradually transform into closed‐cage Cr@Sin structures, with the Mn atom exposed outside. Starting from size 15, both the Cr and Mn atoms are completely encapsulated by silicon atoms. Meanwhile, the Cr and Mn atoms in smaller‐sized CrMnSin (n = 4–7) clusters tend to be separated, while they prefer to stay together for larger sizes. Cr atom always acts as electron donor, but not for Mn atom. From the average binding energies, one can conclude that it is easier to form larger size clusters. Smaller and larger sized CrMnSin (n = 4–9 and 19–20) clusters prefer to exhibit ferromagnetic Cr–Mn coupling, while sizes n = 10–18 always exhibit ferrimagnetic state. To our knowledge, the CrMnSin clusters is the first kind of neutral transition‐metal doped semiconductor clusters that show ferrimagnetic state within a wide size range. [ABSTRACT FROM AUTHOR]

Herein, we explored the structures and electronic properties of transition metal (TM)-doped tin clusters TMSn15–17− (TM = Sc, Y, Ti, Zr, Hf) at density functional theory (DFT) level. Global search was performed for the global minimum isomers of these clusters by using the genetic algorithm coupled with the DFT calculations. The simulated photoelectron spectra for the lowest energy isomers are in good agreement with the experimental results, indicating the identification of the right structures. All TMSn15− (TM = Sc, Y, Ti, Zr, Hf) clusters adopt the same endohedral TM@Sn15 structure, while all TMSn16− clusters are the Frank–Kasper (FK) polyhedron. Additionally, all these TMSn17− clusters are based on the FK polyhedron with an extra Sn atom absorbed on the surface. From the average binding energies and embedding energies, it has been observed that the larger the atomic number of dopant atom, the worse the structural stability for TMSnn− (TM = Ti, Zr, Hf) clusters. The anionic TMSn16− (TM = Sc, Y) and neutral TMSn16 (TM = Ti, Zr, Hf) are identified as superatoms with the same closed electronic shell configuration of (1S)2(1P)6(1D)10(1F)14(2S)2(1G)18(2P)6(2D)10. In this work, the structural evolution and electronic properties of transition metal (TM)-doped tin clusters TMSn15− (TM= Sc, Y, Ti, Zr, Hf) were investigated by using a self-developed genetic algorithm code coupled with density functional theory (DFT) calculations. [ABSTRACT FROM AUTHOR]

Herein, microchip laser-based laser-ablation spark-induced breakdown spectroscopy (LA-SIBS) was developed to realize the quantitative elemental analysis of minor elements in bismuth brass with minimal destruction. A simple spark discharge unit and compact multichannel fiber spectrometer in non-gated operation mode were employed. The characteristics of spark discharge were analyzed, and the effects of discharge voltage and capacitance of the energy storage capacitor on the signal intensities were studied. With the assistance of spark discharge, the plasma temperature increased significantly. The detection limits of bismuth and tin were determined to be 21.6 ± 1.1 and 100 ± 5 ppm, respectively, demonstrating a 10–22-fold enhancement in the detection limit obtained by microchip laser-based LIBS. It was shown that spark discharge could improve the analytical sensitivity of the portable LA-SIBS system. This work can help construct a portable and miniaturized system to realize more rapid, sensitive, and high spatial resolution online elemental analysis than LIBS systems consisting of the same microchip laser and fiber spectrometer. [ABSTRACT FROM AUTHOR]