The photoelectron spectra of chromium-doped silicon cluster anions, CrSi-(n), were measured over the size range, n=8-12. Their vertical detachment energies were measured to be 2.71, 2.88, 2.87, 2.95, and 3.18 eV, respectively. Our results support theoretical calculations by Khanna, Rao, and Jena [Phys. Rev. Lett. 89, 016803 (2002)] which found CrSi12 to be an enhanced stability (magic) cluster with its chromium atom encapsulated inside a silicon cage and with its magnetic moment completely quenched by the effects of the surrounding cage.
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http://dx.doi.org/10.1063/1.1851984 | DOI Listing |
Phys Chem Chem Phys
June 2023
Quantum Solid State Physics, KU Leuven, Celestijnenlaan 200D, B-3001 Leuven, Belgium.
A series of small chromium-doped silicon clusters with = 3-10 in the cationic, neutral and anionic charge states were investigated using quantum chemical methods. The CrSi cations with = 6-10 were produced in the gas phase and characterized by far-IR multiple photon dissociation (IR-MPD) spectroscopy. Good agreement between experimental spectra in the 200-600 cm frequency range and those determined for the lowest-energy isomers by density functional theory calculations (B3P86/6-311+G(d)) provide a strong support for the geometrical assignments.
View Article and Find Full Text PDFChem Mater
April 2021
Wigner Research Centre for Physics, Institute for Solid State Physics and Optics, P.O. Box 49, Budapest H-1525, Hungary.
X-ray-activated near-infrared luminescent nanoparticles are considered as new alternative optical probes due to being free of autofluorescence, while both their excitation and emission possess a high penetration efficacy . Herein, we report silicon carbide quantum dot sensitization of trivalent chromium-doped zinc gallate nanoparticles with enhanced near-infrared emission upon X-ray and UV-vis light excitation. We have found that a ZnGaO shell is formed around the SiC nanoparticles during seeded hydrothermal growth, and SiC increases the emission efficiency up to 1 order of magnitude due to band alignment that channels the excited electrons to the chromium ion.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2019
Analytical & Testing Center , Sichuan University, Chengdu , Sichuan 610064 , China.
Near-infrared (NIR) persistent luminescence (PersL) nanoparticles based on trivalent chromium-doped gallates (ZGO) as nanocarriers show great potential for theranostics, owing to their autofluorescence-free background and deep tissue penetration. However, high drug loading capacity of ZGO nanocarriers remains a big challenge. Herein, raspberry-like mesoporous ZnGaSiO:Cr (designated as Si-ZGO) is first developed via a unique silica-assisted targeted etching strategy.
View Article and Find Full Text PDFWe describe a compact and efficient mid-infrared (mid-IR) source based on zinc germanium phosphide (ZGP) and cadmium silicon phosphide (CSP) optical parametric oscillators (OPOs), operating in near degenerate condition, directly pumped by a 1.94 μm thulium (Tm)-doped yttrium-aluminum-perovskite (YAP) laser. The Tm:YAP laser is passively Q-switched by a chromium-doped zinc sulfide saturable absorber, and is operated to 4 W average power with a peak power of 29 kW.
View Article and Find Full Text PDFACS Appl Mater Interfaces
November 2017
MOE Key Laboratory for Analytical Science of Food Safety and Biology, State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry and ‡College of Biological Science and Engineering, Fuzhou University, Fuzhou 350116, P. R. China.
Persistent luminescence nanoparticles (PLNPs) have great potential for bioimaging because they can eliminate the tissue autofluorescence and improve the signal-to-noise ratio significantly. High-temperature calcination is a necessary process for the PLNPs to achieve high luminescence intensity and long afterglow time. However, high-temperature calcination usually results in uncontrollable morphology and poor homogeneity of PLNPs, which greatly limit their applications.
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