Sergiu V Nistor

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Neuroglobin is a recently discovered member of the globin superfamily. Combined electron paramagnetic resonance and optical measurements show that, in Escherichia coli cell cultures with low O(2) concentration overexpressing wild-type mouse recombinant neuroglobin, the heme protein is mainly in a hexacoordinated deoxy ferrous form (F8His-Fe(2+)-E7His),(More)
Accurate determination of the spin Hamiltonian (SH) parameters, describing the electron paramagnetic resonance (EPR) spectra of paramagnetic impurity ions in wide band gap semiconductor nanocrystals, is essential for determining their localization and quantum properties. Here we present a procedure, based on publicly available software, for determining with(More)
The X (9.8 GHz)-band electron paramagnetic resonance (EPR) properties of substitutional Mn(2+) ions in high quality cubic ZnS single crystals grown from PbCl(2) flux have been thoroughly investigated. Accurate spin Hamiltonian (SH) parameters: g = 2.002 25 ± 0.000 06; a = (7.987 ± 0.008) × 10(-4) cm(-1) and A = -(63.88 ± 0.02) × 10(-4) cm(-1) were obtained(More)
The damage threshold of fused silica in vacuum and air before or after 355nm laser irradiation is measured. The structure and defects of fused silica has been studied by means of FTIR (Fourier transform infrared), Raman and Fluorescence spectroscopy. The primary defect species are oxygen vacancies (such as Si–Si bonds), non-bridging oxygen hole center(More)
Several reviews concerning the EPR of the paramagnetic transition-metal ions in crystals are now available, either as periodic reports published in the Magnetic Resonance Review, or in books [1,2,3] and review papers [4, 5]. Such paramagnetic centers are usually observed in the as grown crystals, the paramagnetic state being the normal valency state of the(More)
Nanocrystalline cubic ZnS doped with 0.2% mol manganese, exhibiting a stable mesoporous structure, was synthesized at room temperature by a non toxic surfactant-assisted liquid-liquid reaction. The X-ray diffraction measurements demonstrate the formation of a sponge-like mesoporous material built from cubic ZnS nanocrystals of 1.8 nm average sizes, with a(More)
A mesoporous structure of self-assembled nanocrystals of cubic ZnS doped with Mn2+ ions with a homogeneous distribution of pores of similar size was synthesized at room temperature by a surfactant-assisted liquid-liquid reaction. The component nanocrystals exhibit a high crystallinity and a tight size distribution centered at 2 nm, as well as the narrowest(More)
An experimental arrangement is devised by which the absorption coefficient of low-loss materials can be measured by calorimetry using pulsed CO(2) lasers. The values obtained for long rod KCl samples are compared with those inferred when a cw CO(2) laser was used as radiation source. The values measured in the pulsed regime are little affected by the(More)
The sites of incorporation of Cu(2+) impurity ions in Bi12GeO20 single crystals co-doped with copper and vanadium have been investigated by electron paramagnetic resonance (EPR). While the X-band EPR spectra consist of a simple broad (ΔB ∼50 mT) line with anisotropic lineshape, the W-band EPR spectra exhibit well resolved, strongly anisotropic lines, due to(More)
A multifrequency electron paramagnetic resonance (EPR) investigation of Nd(3+) impurities in PbWO(4) single-crystals at the conventional microwave frequency (MF) 9.43 GHz, and at the 95, 190, and 285 GHz high frequencies was carried out. The resulting spectra are well described at all frequencies by an axial spin-Hamiltonian corresponding to an effective(More)
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