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H3BO3 was used as the sintering additive to enable Zn0.997Cu0.003ZrNb2O8 ceramics to accomplish low‐temperature sintering and outstanding microwave dielectric performances. Composite ceramics were created using typical solid‐state processes. The effects of added H3BO3 on the sintering behavior, microstructural characteristics, vibrational properties, and microwave dielectric performances of Zn0.997Cu0.003ZrNb2O8 + x wt% H3BO3 (2 ≤$ \le $ x ≤$ \le $ 8) ceramics have been systematically investigated by means of X‐ray diffraction, Raman scattering spectroscopy, scanning electron microscopy, and complex chemical bond theory. The results of relative density and microscopic morphology demonstrated that the application of an adequate quantity of H3BO3 additive can significantly enhance sintering properties. The doped H3BO3 alters the inter‐ionic interactions so that the structural features become intrinsic to the microwave dielectric performances. The particularly satisfactory microwave dielectric performances (εr${\varepsilon }_r$ = 10.61, Q×f$ Q \times f $ = 33 980 GHz, and τf${\tau }_f$ = ‐45.10 ppm/°C) were detected in x = 6 ceramic specimens sintered at 950°C, which would make it promising for use in modern low temperature co‐fired ceramics technology. [ABSTRACT FROM AUTHOR]

The lattice dynamical properties of dilute InAs1−xNx/InP (001) epilayers (0 ≤ x ≤ 0.03) grown by gas-source molecular beam epitaxy were carefully studied experimentally and theoretically. A high-resolution Brüker IFS 120 v/S spectrometer was employed to measure the room-temperature infrared reflectivity (IRR) spectra at near-normal incidence (θi = 0). The results in the frequency range of 180–500 cm−1 revealed accurate values of the characteristic In-As-like and In-N-like vibrational modes. For InAs1−xNx alloys, a classical "Drude–Lorentz" model was constructed to obtain the dielectric functions ε ~ ω in the far IR regions by incorporating InAs-like and InN-like transverse optical ω T O modes. Longitudinal optical ω L O phonons were achieved from the imaginary parts of the simulated dielectric loss functions. The theoretical results of IRR spectra for InAs1−xNx/InP (001) epilayers using a multi-layer optics methodology provided a very good agreement with the experimental data. At oblique incidence (θi ≠ 0), our study of s- and p-polarized reflectance (Rs,p(ω)) and transmission (Ts,p(ω)) spectra allowed the simultaneous perception of the ω T O and ω L O phonons of the InAs, InN and InAs0.97N0.03 layers. Based on the average t-matrix Green's function theory, the results of local vibrational modes for light S i I n + donors and S i A s − ,   C A s − acceptors in InAs were found in good agreement with the existing Raman scattering and infrared spectroscopy data. I n I n N , however, the method predicted an in-band mode for the M g I n − acceptor while projecting an impurity mode of the S i I n + donor to appear just above the maximum ω m a x I n N [ ≡ 595   c m − 1 ] phonon frequency region. In InAs1−xNx/InP (001) epifilms, the comparison of reflectivity/transmission spectra with experiments and the predictions of impurity modes for isoelectronic donor and acceptor impurities in InAs and InN can be valuable for appraising the role of defects in other technologically important semiconductors. [ABSTRACT FROM AUTHOR]

Experimental and theoretical assessments of phonon and optical characteristics are methodically accomplished for comprehending the vibrational, structural, and electronic behavior of InP1−xSbx/n-InAs samples grown by Gas-Source Molecular Beam Epitaxy. While the polarization-dependent Raman scattering measurements revealed InP-like doublet covering optical modes ( ω L O I n P ~ 350 cm−1, ω T O I n P ~ 304 cm−1) and phonons activated by disorders and impurities, a single unresolved InSb-like broadband is detected near ~195 cm−1. In InP1−xSbx, although no local vibrational (InSb:P; x → 1) and gap modes (InP:Sb; x → 0) are observed, the Raman line shapes exhibited large separation between the optical phonons of its binary counterparts, showing features similar to the phonon density of states, confirming "two-mode-behavior". Despite the earlier suggestions of large miscibility gaps in InP1−xSbx epilayers for x between 0.02 and 0.97, our photoluminescence (PL) results of energy gaps insinuated achieving high-quality single-phase epilayers with x ~ 0.3 in the miscibility gap. Complete sets of model dielectric functions (MDFs) are obtained for simulating the optical constants of binary InP, InSb, and ternary InP1−xSbx alloys in the photon energy (0 ≤ E ≤ 6 eV) region. Detailed MDF analyses of refractive indices, extinction coefficients, absorption and reflectance spectra have exhibited results in good agreement with the spectroscopic ellipsometry data. For InP0.67Sb0.33 alloy, our calculated lowest energy bandgap E0 ~ 0.46 eV has validated the existing first-principles calculation and PL data. We feel that our results on Raman scattering, PL measurements, and simulations of optical constants provide valuable information for the vibrational and optical traits of InP1−xSbx/n-InAs epilayers and can be extended to many other technologically important materials. [ABSTRACT FROM AUTHOR]

The long-range crystallographic order and anisotropy in β-(AlxGa1−x)2O3 (x = 0.0, 0.06, 0.11, 0.17, 0.26) crystals, prepared by optical floating zone method with different Al composition, is systematically studied by spatial correlation model and using an angle-resolved polarized Raman spectroscopy. Alloying with aluminum is seen as causing Raman peaks to blue shift while their full widths at half maxima broadened. As x increased, the correlation length (CL) of the Raman modes decreased. By changing x, the CL is more strongly affected for low-frequency phonons than the modes in the high-frequency region. For each Raman mode, the CL is decreased by increasing temperature. The results of angle-resolved polarized Raman spectroscopy have revealed that the intensities of β-(AlxGa1−x)2O3 peaks are highly polarization dependent, with significant effects on the anisotropy with alloying. As the Al composition increased, the anisotropy of Raman tensor elements was enhanced for the two strongest phonon modes in the low-frequency range, while the anisotropy of the sharpest Raman phonon modes in the high-frequency region decreased. Our comprehensive study has provided meaningful results for comprehending the long-range orderliness and anisotropy in technologically important β-(AlxGa1−x)2O3 crystals. [ABSTRACT FROM AUTHOR]

The lattice dynamical properties of dilute InAs1−xNx/InP (001) epilayers (0 ≤ x ≤ 0.03) grown by gas-source molecular beam epitaxy were carefully studied experimentally and theoretically. A high-resolution Brüker IFS 120 v/S spectrometer was employed to measure the room-temperature infrared reflectivity (IRR) spectra at near-normal incidence (θi = 0). The results in the frequency range of 180–500 cm−1 revealed accurate values of the characteristic In-As-like and In-N-like vibrational modes. For InAs1−xNx alloys, a classical “Drude–Lorentz” model was constructed to obtain the dielectric functions ε~ω in the far IR regions by incorporating InAs-like and InN-like transverse optical ωTO modes. Longitudinal optical ωLO phonons were achieved from the imaginary parts of the simulated dielectric loss functions. The theoretical results of IRR spectra for InAs1−xNx/InP (001) epilayers using a multi-layer optics methodology provided a very good agreement with the experimental data. At oblique incidence (θi ≠ 0), our study of s- and p-polarized reflectance (Rs,p(ω)) and transmission (Ts,p(ω)) spectra allowed the simultaneous perception of the ωTO and ωLO phonons of the InAs, InN and InAs0.97N0.03 layers. Based on the average t-matrix Green’s function theory, the results of local vibrational modes for light SiIn+ donors and SiAs−, CAs− acceptors in InAs were found in good agreement with the existing Raman scattering and infrared spectroscopy data. InInN, however, the method predicted an in-band mode for the MgIn− acceptor while projecting an impurity mode of the SiIn+ donor to appear just above the maximum ωmaxInN[≡595 cm−1] phonon frequency region. In InAs1−xNx/InP (001) epifilms, the comparison of reflectivity/transmission spectra with experiments and the predictions of impurity modes for isoelectronic donor and acceptor impurities in InAs and InN can be valuable for appraising the role of defects in other technologically important semiconductors.

Experimental and theoretical assessments of phonon and optical characteristics are methodically accomplished for comprehending the vibrational, structural, and electronic behavior of InP1−xSbx/n-InAs samples grown by Gas-Source Molecular Beam Epitaxy. While the polarization-dependent Raman scattering measurements revealed InP-like doublet covering optical modes (ωLOInP~350 cm−1, ωTOInP~304 cm−1) and phonons activated by disorders and impurities, a single unresolved InSb-like broadband is detected near ~195 cm−1. In InP1−xSbx, although no local vibrational (InSb:P; x → 1) and gap modes (InP:Sb; x → 0) are observed, the Raman line shapes exhibited large separation between the optical phonons of its binary counterparts, showing features similar to the phonon density of states, confirming “two-mode-behavior”. Despite the earlier suggestions of large miscibility gaps in InP1−xSbx epilayers for x between 0.02 and 0.97, our photoluminescence (PL) results of energy gaps insinuated achieving high-quality single-phase epilayers with x ~ 0.3 in the miscibility gap. Complete sets of model dielectric functions (MDFs) are obtained for simulating the optical constants of binary InP, InSb, and ternary InP1−xSbx alloys in the photon energy (0 ≤ E ≤ 6 eV) region. Detailed MDF analyses of refractive indices, extinction coefficients, absorption and reflectance spectra have exhibited results in good agreement with the spectroscopic ellipsometry data. For InP0.67Sb0.33 alloy, our calculated lowest energy bandgap E0 ~ 0.46 eV has validated the existing first-principles calculation and PL data. We feel that our results on Raman scattering, PL measurements, and simulations of optical constants provide valuable information for the vibrational and optical traits of InP1−xSbx/n-InAs epilayers and can be extended to many other technologically important materials.

Micro Raman tomographic imaging (mRTI) is an excellent measurement technique that can nondestructively measure and image the fracture state of the crystal lattice inside materials with a high spatial resolution. mRTI has been successfully used for translucent materials such as wide bandgap semiconductor wafers. The applicability of this measurement method was evaluated by observing the wear damage in polycrystalline industrial ceramics materials. The influence of optical diffusion on the surface and inside of polycrystalline materials is a concern for the internal measurements by the optical beam. The quality degradation of spectral signals due to disturbances in the optical beam was confirmed by mRTI measurements on a commercial alumina plate. The application of surface polishing treatment was attempted to reduce the influence of surface optical diffusion. Three kinds of the surfaces were observed by mRTI, as the initial surface of the alumina plate, polished with #400 and #800 diamond abrasive lapping film, respectively. It was confirmed that the effective measurement depth range can be extended by reducing the surface roughness. However, we confirmed that excessive surface polishing may overwrite the damage on the measurement surface, making it difficult to observe the original damage.

The long-range crystallographic order and anisotropy in β-(AlxGa1−x)2O3 (x = 0.0, 0.06, 0.11, 0.17, 0.26) crystals, prepared by optical floating zone method with different Al composition, is systematically studied by spatial correlation model and using an angle-resolved polarized Raman spectroscopy. Alloying with aluminum is seen as causing Raman peaks to blue shift while their full widths at half maxima broadened. As x increased, the correlation length (CL) of the Raman modes decreased. By changing x, the CL is more strongly affected for low-frequency phonons than the modes in the high-frequency region. For each Raman mode, the CL is decreased by increasing temperature. The results of angle-resolved polarized Raman spectroscopy have revealed that the intensities of β-(AlxGa1−x)2O3 peaks are highly polarization dependent, with significant effects on the anisotropy with alloying. As the Al composition increased, the anisotropy of Raman tensor elements was enhanced for the two strongest phonon modes in the low-frequency range, while the anisotropy of the sharpest Raman phonon modes in the high-frequency region decreased. Our comprehensive study has provided meaningful results for comprehending the long-range orderliness and anisotropy in technologically important β-(AlxGa1−x)2O3 crystals.

The particulars of the effect of focused femtosecond laser pulses on antimony silicate glass with the composition 25Sb2O3∙75SiO2 % (molar content) in thermal and athermal regimes were studied. It was found that in contrast to quartz, alkali silicate, and some borosilicate glasses the birefringence of the form characteristic for the formation of nanogratings does not arise in the laser-modified zones of the studied glass. Weak birefringence with slow axis parallel to the polarization plane of the writing laser beam, accompanied by precipitation of crystalline phases, seemingly including the cubic modification of Sb2O3, arises in the modified zones under irradiation by 106 pulses with energy > 100 nJ and repetition frequency 10 and 200 kHz. [ABSTRACT FROM AUTHOR]

Densified Ba1−xLaxSnO3 (BLSO) ceramics were synthesized at relatively lower sintering temperature by a conventional solid state reaction route. X-ray diffraction (XRD) analysis using the Reitveld refinement technique inferred cubic (space group Pm–3m) average crystalline structure. The effect of La-substitution on variations of lattice parameters could be attributed to two competing factors, viz. ionic radii of the dopant and partial reduction of Sn4+ into Sn2+. XRD data indicate local symmetry reduction from cubic to orthorhombic (Pbnm), evident from the observed splitting in {211}p and {310}p peaks of pseudo cubic structure, as well as corresponding super reflections. The synthesized ceramics were highly porous with percentage densification in the range (60–70)% due to the relatively low sintering temperature used. Densification was improved using 2 wt.% Bi2O3 as a sintering aid, which resulted in highly dense ceramics with relative density ≈ 95%. Sintering temperature reduction of ≈ 300°C was also achieved relative to that required in normal solid state synthesis. This is very important to reduce defects and inhibit uneven grain growth. Microstructure and elemental analysis probed through scanning electron microscopy and energy-dispersive x-ray spectroscopy revealed that Bi replaces lanthanum and that liquid phase sintering is mainly responsible for the high densification using the sintering aid. The structural indicators of symmetry reduction were corroborated by experimentally observed Raman modes in an otherwise symmetry-forbidden cubic phase. The local symmetry reduction is attributed mainly to octahedral tilts corresponding to orthorhombic symmetry. [ABSTRACT FROM AUTHOR]

Nanoporous glass is a universal matrix in which impregnation with different substances can trigger the appearance of properties which are uncharacteristic for glass. Heat treatment, creating material with a specified structure and properties, can be used to control the porosity of the glass. In the present work the effect of heat treatment on the structure of gold-impregnated porous glass was studied and it became apparent that this material has potential as an active substrate for Raman scattering spectroscopy. [ABSTRACT FROM AUTHOR]

Flexural elastic deformations of single-crystal silicon have been studied using microspectral Raman scattering. Results are reported on nano-scaled sign-changing shifts of the main peak of the microspectral Raman scattering within the single-crystal silicon cantilever beam during exposure to flexural stress. The maximum value of Raman shift characteristic of the 518 cm−1 silicon peak at which elasticity still remains has been found to be 8 cm−1 which corresponds to an applied deformation of 4 GPa. We report three-dimensional maps of the distribution of internal stresses at different levels of deformation up to irreversible changes and brittle fracture of the samples that clearly show compression and tension areas and an undeformed area. A qualitative explanation of the increase in the strength of the cantilever beam due to its small thickness (2 μm) has been provided that agrees with the predictions of real-world physical parameters obtained in SolidWorks software environment with the SimulationXpress module. We have defined the relative strain of the beam surface which was 2% and received a confirmation of changes in the silicon lattice parameter from 0.54307 nm to 0.53195 nm by the BFGS algorithm.

Local crystallization of barium titanate silicate glass under the action of femtosecond laser beam was studied. The effect of the scan rate of the laser beam and the energy of the laser pulses on the morphology of the channels containing crystals of fresnoite Ba2TiSi2O8 was determined. Polarization Raman scattering spectroscopy was used to determine the predominant orientation of fresnoite crystals with formed channels. The results open up prospects for developing and fabricating waveguide crystal structures with low optical losses for photonics and integrated optics. [ABSTRACT FROM AUTHOR]

The authors have deposited the diamond-like carbon (DLC) films by radio frequency inductively coupled plasma enhanced chemical vapor deposition (RF ICP PECVD) method. The investigated DLC films with different sp3 fraction content were deposited on polished and textured silicon substrates. The sp3 fraction content of the deposited DLC films was ranging from 35 % to 70 % and was estimated from acquired Raman scattering spectra (excitation wavelength: 325 nm and 514.5 nm). The measurements of field emission characteristics were carried out in diode configuration. Emission properties of the DLC films were calculated from Fowler-Nordheim plots. The calculated electric field enhancement factor β was ranging from 56 to 198 for the DLC films deposited on polished substrates and from 115 to 445 for films deposited on textured substrates. The surface of the DLC films was observed by scanning electron microscope (SEM) after field emission measurements. The acquired SEM images reveled that the activation of field emission from the DLC films is connected with generation of structural damage to the DLC films. [ABSTRACT FROM AUTHOR]

Raman scattering (RS), Fourier transform infrared (FTIR) and electron paramagnetic resonance (EPR) spectroscopic measurements on β -MnO 2 and α -K x MnO 2 nanorods were performed. The infrared spectrum of β -MnO 2 is sensitive towards the particle sizes, while the Raman spectrum is sensitive towards the presence of nonstoichiometric and disordered MnO 2- δ on the surface of nanorods. EPR measurements show the appearance of two types of Mn 4+ ions having different local environment: (i) Mn 4+ ions in Mn 4+ -rich environment and (ii) Mn 4+ ions in mixed-valence Mn 4+ /Mn 3+ environment that match up with region of nonstoichiometric MnO 2- δ . Observed bands in vibrational spectra of tetragonal hollandite-type α -K x MnO 2 are considered to be mainly due to the vibration modes of Mn O frameworks. The EPR spectra of α -K x MnO 2 nanorods contain two signals that can be attributed to Mn 4+ ions in Mn 4+ -rich environment and Mn 4+ ions in mixed-valence Mn 4+ /Mn 3+ environment close to K + ions. [ABSTRACT FROM AUTHOR]

Spectral microscopy provides information about the spatial distribution and physiological functional states of pigment-protein complexes in photosynthetic organisms. This can be used to complement the newly developed techniques, such as cryogenic electron microscopy and atomic force microscopy, which are less effective in functional analysis of photosynthesis, despite having an excellent spatial resolution. The combination of optical microscopies with various spectroscopic techniques has extended the possibility of a multi-perspective investigation in photosynthesis research. Some of these spectroscopic techniques include fluorescence and absorption spectra, excitation spectra, time-resolved fluorescence measurement, Raman scattering spectroscopy, etc. These techniques can be applied to in vivo investigations of photosynthetic activity without introducing any artificial fluorophore since the photosynthetic pigments are informative probes. In particular, the technique has been effective in clarifying the dynamic physiological responses of photosynthetic organisms to variable environments. In this paper, we review the recent progress in spectral microscopy in the field of in vivo photosynthesis research. We have also introduced and discussed some distinctive spectral microscopies such as anti-Stokes fluorescence spectral microscopy, excitation spectral microscopy, cryo-microscopy, and Raman spectral microscopy. • Review and perspective of spectroscopic microscopy in photosynthetic studies. • Fluorescence spectra and excitation spectra are powerful for the multi-pigment system. • Fluorescence lifetime imaging senses dynamics of electronic excitation at microscale. • Absorption and Raman spectral microscopy to quantify nonfluorescent molecules. • Cryo-spectral microscope to observe arrested states during physiological changes. [ABSTRACT FROM AUTHOR]

We report the results of experimental studies on cardiac implants using a Raman spectroscopy method (RS). Raman spectra characteristics of leaves and walls of cardiac implants were obtained; the implants were manufactured by protocols of detergent-enzymatic technique (DET) and biological, detergent-free (BIO) decellularization, using detergents (group DET) or a detergent-free, nonproteolytic, actin-disassembling regimen (BIO). There were input optical coefficients that allowed us to carry out evaluation of the protocols of DET and BIO decellularization on the basis of the concentrations of glycosaminoglycans, proteins, amides, and DNA. It was shown that during DET and BIO decellularization, composition aberrations of proteins and lipids do not occur and the integrity of the collagenous structures is preserved. It was found that during the DET decellularization, preservation of glycosaminoglycans is better than during BIO decellularization. [ABSTRACT FROM AUTHOR]

Recently Cu 2 ZnSnS 4 , i.e. Copper Zinc Tin Sulphide (CZTS), has emerged as a potential candidate for low-cost solar photovoltaics (PV) material because of it is relatively non-toxic and ingredient elements are earth abundant. However, achieving phase controlled, stoichiometric film of CZTS using low-cost technique is the key issue in development of CZTS based solar cell. Here, we report a study on structural and optical properties of CZTS films grown by dip-coating in view of its application as an absorber in thin film solar cells. The films were deposited by dipping glass substrates into the solution prepared by dissolving cation metal salts and thiourea in methanol. It is followed by drying the films in air at fixed temperature. The dip coated films were then annealed at 623 K, 723 K and 823 K. The influence of annealing on various structural and optical properties of the films were investigated by means of X-ray diffraction (XRD), Raman scattering spectroscopy, Scanning electron microscopy (SEM) and Diffused reflection spectroscopy. It was observed that the film annealed at 823 K shows good quality Kesterite structure of CZTS with preferred orientation of (112), (220) and (312) planes as revealed by the XRD pattern. The diffuse reflection spectra confirm the direct band-gap of 1.42 eV, which is very close to the optimum value for the semiconductor material as an absorber in solar-cells. Raman scattering with two different excitation wavelengths showed that other binary phases including the parasitic phases such as ZnS were not present. It also confirmed the characteristics signature of dominant CZTS phase in the film. [ABSTRACT FROM AUTHOR]

Comprehensive results of experimental and theoretical studies are reported to probe the optical, phonon, thermal and defect properties of 3C–SiC/Si (001). By exploiting phonon-assisted Raman scattering (RS) spectroscopy we have recognized, among the conventional optical modes [TO(Γ) ~ 796 cm − 1 and LO(Γ) ~ 973 cm − 1 ], two extra phonon features near ~ 625 cm − 1 and 670 cm − 1 — possibly falling between the forbidden gap of the acoustic and optical branches. Temperature dependent profile of the unresolved ~ 670 cm − 1 band has indicated disordering by nearby defects and/or stress — rendering shorter phonon lifetime to instigate mode broadening. Accurate assessments of the lattice dynamical, thermal and defect properties are achieved by exploiting phonons from a rigid-ion model fitted to the inelastic x-ray scattering data and expending apposite group-theoretical selection rules. Lattice relaxations around Si/C atoms attained by the first-principles bond-orbital model for isolated defects have helped us to evaluate the necessary force constant variations for constructing perturbation matrices of the “complex-defect-centers”. For isolated anti-site C Si and Si C defects ( T d -symmetry), our methodical Green's function (GF) theory has predicted triply degenerate F 2 gap modes near 630 cm − 1 and 660 cm − 1 , respectively. The GF simulations of impurity vibrations for a neutral nearest-neighbor anti-site Si C –C Si pair-defect ( C 3v -symmetry) provided gap-modes to appear within the broad ~ 670 cm − 1 band at 664.8 cm − 1 ( a 1 ) and 660.6 cm − 1 ( e ). The calculated results of localized vibrational modes are compared and discussed with phonon features observed in the RS experiments as well as with the density function theory. [ABSTRACT FROM AUTHOR]

Flexural elastic deformations of single-crystal silicon with microspectral Raman scattering are studied. The investigation results are given on nano-scaled sign-changing shifts of the main peak of the microspectral Raman scattering within the single-crystal silicon cantilever beam under influence of flexural stress. The maximum value of Raman shift characteristic of silicon peak equal to 518 cm-1, when elasticity still remains, amounted to 8 cm-1. The qualitative explanation of increase in strength of the cantilever beam due to its small thickness (2 μm) is provided, which is in accord with predictions of real-world physical parameters that were obtained in software environment SolidWorks with the module SimulationXpress. [ABSTRACT FROM AUTHOR]

SmBa2Cu3O7 (SmBCO)-coated conductors were grown on IBAD-MgO templates by in-situ co-evaporation using a drum-in-dual-chambers system. The conductors, which had a coating thickness of up to 3 \mum, showed a critical temperature of 92 \sim 94 K and a critical current of 150 \sim 625 A/cm-w at 77 K in a self-field. The phonon modes and cation disorder of the SmBCO-coated conductors were examined by polarized Raman scattering spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy. XRD showed (00l) peaks for the SmBCO phase. The Raman spectra revealed common vibration modes, including Ba-Ba stretching, Cu2-Cu2 stretching, O(2)+/O(3)-, and apical O(4) modes. In addition, polarized-Raman spectra were obtained to examine the crystal orientation and grain growth behavior. Structural information from the Raman spectra turned out to be useful to determine the optimal thickness of SmBCO-coated conductors with high critical currents. [ABSTRACT FROM AUTHOR]

Abstract: The low temperature sensibility and the thermal stability in air of amorphous diamond (a-D) films deposited by filtered arc have been investigated with visible Raman spectroscopy. The films cooled in a range of room temperature to −190 °C by a liquid nitrogen pump were in-situ measured on a Linkam stage. The films for thermal stability were heated in a furnace. It has been found that the films are thermally very stable in air. They can hold their hardness up to 400 °C and their structure up to 500 °C. However, complete material loss occurs if the temperature is continuously raised. Raman measurements show a shift of the G-peak frequency to higher values with increasing temperature. The films are not sensitive to low temperature and remain stable as temperature is decreased down to −190 °C. [Copyright &y& Elsevier]

[Ni(ND3)6](ClO4)2 has three solid phases between 100 and 300 K. The phase transitions temperatures at heating (TC1h=164.1 K and TC2h=145.1 K) are shifted, as compared to the non-deuterated compound, towards the lower temperature of ca. 8 and 5 K, respectively. The ClO4- anions perform fast, picosecond, isotropic reorientation with the activation energy of 6.6 kJ mol-1, which abruptly slow down at TC1c phase transition, during sample cooling. The ND3 ligands perform fast uniaxial reorientation around the Ni–N bond in all three detected phases, with the effective activation energy of 2.9 kJ mol-1. The reorientational motion of ND3 is only slightly distorted at the TC1 phase transition due to the dynamical orientational order–disorder process of anions. The low value of the activation energy for the ND3 reorientation suggests that this reorientation undergoes the translation–rotation coupling, which makes the barrier to the rotation of the ammonia ligands not constant but fluctuating. The phase polymorphism and the dynamics of the molecular reorientations of the title compound are similar but not quite identical with these of the [Ni(NH3)6](ClO4)2. [Copyright &y& Elsevier]

Chalcogenide vitreous semiconductors (ChVS) are used as memory elements, elements of fiber, integral and power optics [1-6]. The change of the synthesis conditions results in the change of structure and, as a consequence, physical parameters of Ch VS [1]. It means that it is possible to find solution of the fabrication of glasses with high optical strength by using modification of ChVS structure [2]. The objective of the present work is to investigate the influence of the temperature-temporal conditions of the fabrication on the structure of As2S3 glasses by the method of the Raman scattering spectroscopy and electron microscopy and also to choose the conditions of fabrication of As2S3 glasses with the continuously bonded matrix of the structure suitable for power optics using this basis. [ABSTRACT FROM AUTHOR]