In situ thermo‐Raman spectroscopy and ab initio vibrational assignment calculations of cubanite CuFe₂S₃

Abstract

In situ thermo‐Raman spectroscopy is used to study a single crystal of natural orthorhombic cubanite from the Talnakh copper‐nickel sulfide deposit (Norilsk, Russia). The dependence of the wavenumbers and FWHMs of vibrational modes on temperature, including the cubanite → isocubanite phase transition region, is studied in the range of 83–873 K. For the first time, the polarized Raman spectra of cubanite have been interpreted according to ab initio calculations performed using the density functional theory (DFT) implemented in the VASP package. In spite of the tetrahedral environment of Cu and Fe atoms in cubanite, the spectra demonstrate the presence of different types of bending (twisting, wagging, scissoring, etc.) and stretching vibrations in two different triatomic (S2‐Cu‐S2) and (Fe‐S1‐Fe) fragments for Ag and B2g symmetries, and in three‐ and four‐atomic (S1‐Cu‐S1) and FeS(2)3 fragments, respectively, for B1g and B3g symmetries.

Temperature Raman study of Li4Ti5O12 and ambiguity in the number of its bands

“…It should be noted that the normal thermal shift toward lower wavenumbers is also typical for other lithium battery electrode materials, namely, LFP 29 and LCO. 30 Characteristic Raman bands of sodium battery materials 31,32 and of many other materials [33][34][35] also demonstrated such a behavior.…”

Sensing Mechanism of Cysteine Specific Fluorescence Probes and Their Application of Cysteine Recognition

“…The innovative novel dyad for FRET is formed from sulfonyl benzoxadiazole (SBD) and coumarin chromophore that relates to a rigid group of piperazine, and this configuration serves as a dual-channel signal reporter for fluorescence and the chlorine unit located at the 4-position of chromophore SBD acts as the Cys specific recognition site. The author observed that FRET is activated when probe Cou-SBD-Cl is exposed for Cys, and a fresh yellow fluorescence emission with a remarkable 56.1-fold increased radio signal and a significant 99 nm emission shift is produced . Therefore, the author has developed ratiometric Cou-SBD-Cl fluorescent probes that followed the Cou-SBD FRET mechanism for the specific identification of Cys, which can be seen in Figure …”