Germanium Sulfide Research Articles

Phase relationships in mixed metal germanium sulfide systems (Mn 2GeS 4T 2GeS 4, where T = Co, Ni, Zn)

The influence of substitution of Mn 2+ by Co 2+, Ni 2+, and Zn 2+ in the olivine Mn 2GeS 4 has been investigated by x-ray powder methods on polycrystalline samples. Contrary to similar systems starting from spinel type compounds we could not obtain new layered materials in these systems. A series of olivine type mixed crystals are formed in the system Mn 2−xCo xGeS 4 for 1 ≥ x ≥ 0. In the corresponding Ni system the olivine type region reaches from x = 0 to at least x = 1.7. Zn 2+ cannot replace Mn 2+ in the olivine structure. Substitution of Zn 2+ in Zn 2GeS 4 by Mn 2+ changes the structure from a defect sphalerite to defect wurtzite type. Co 2GeS 4 and Ni 2GeS 4 could not be obtained.

Infrared spectra of germanium sulfide, germanium disulfide, germanium oxide sulfide and germanium dioxide in solid argon

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTInfrared spectra of germanium sulfide, germanium disulfide, germanium oxide sulfide and germanium dioxide in solid argonParviz Hassanzadeh and Lester AndrewsCite this: J. Phys. Chem. 1992, 96, 15, 6181–6185Publication Date (Print):July 1, 1992Publication History Published online1 May 2002Published inissue 1 July 1992https://doi.org/10.1021/j100194a018RIGHTS & PERMISSIONSArticle Views490Altmetric-Citations33LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (592 KB) Get e-Alerts

Short and medium range order in germanium sulfide glasses: a low temperature X-ray absorption spectroscopy study

Ge K-edge EXAFS measurements were carried out at 35 K for GeSx (1.5 ≤ x ≤ 5) binary glasses and (1−y)GeS2 + yAg2S (0 ≤ y ≤ 0.4) glassy compositions. The three first Ge coordination shells were resolved. Thus, the short range order around germanium atoms located in tetrahedral sites has been confirmed. Then, knowledge of the medium range order existing in these glasses was improved, particularly on clustering of GeS4 tetrahedral units by edges or corners. Further, both the depolymerization rates of edge and corner sharing GeS4 tetrahedra have been estimated by reference to αGeS2 structure. The (g)GeS2 structure is mainly constituted by two-dimensional clusters based on αGeS2 crystalline structure. In this case the depolymerization fractions are both equal to about 40%. When the atomic composition deviates from the GeS2 stoichiometry for GeSx binary glasses, or when Ag2S is added to the GeS2 glass former, a significant increase of the depolymerization of both corner and edge linkages is noted. This increase implies an increase of the structural distortion in the local and mainly in the intermediate range order.

Photodissolution of silver in amorphous germanium sulphide films

The results of the first systematic study of photodissolution of silver in amorphous germanium sulphide films are reported. The kinetics of the photodissolution process have been investigated by monitoring the time dependence of the resistance of the Ag film under illumination by UV light. By contrast with the behaviour found in other chalcogenide materials, an induction period was not observed before the onset of photodissolution; instead, the process consisted of an acceleratory phase followed by a deceleratory phase. The maximum photodissolution rate was studied as a function of light intensity and wavelength, and also of temperature.

Photoconductivity in single-crystal germanium sulphide

The photoconductivity spectral response was measured for germanium sulphide (GeS) single crystals at different temperatures from room temperature to near liquid-nitrogen temperature. Measurements were carried out with plane-polarised light with the plane of polarisation parallel to the a and b crystallographic axes, which lie in the plane of cleavage. The photon energy range of measurements extended from 1.0 to 3.5 eV. The photoconductivity energy gap was determined from the spectral response by the Moss rule. The room-temperature photoconductivity energy gap was found to be 1.613+or-0.010 and 1.642+or-0.028 eV for the a and b axes, respectively. The temperature dependence of the photoconductivity energy gap was also deduced. It was found that it is linear between 92 and 300 K with a negative temperature coefficient equal to -0.43+or-0.01 meV K-1 for the a axis. The results for the b axis showed a large discrepancy, which was attributed to crystal lattice bending introduced during the cleavage process. The minority-carrier lifetime was determined from the photoconductivity frequency response, which was found to be characterised by two different lifetimes.

EPR study of different states of iron impurity in chalcogenide glasses

The behaviors of iron impurities in a number of chalcogenide glasses (based on vitreous compounds AgAsS 2 and As 2S 3, and on germanium sulfides and selenides) have been studied by the EPR method. Several new paramagnetic iron centers have been found along with one reported earlier. Attribution on EPR spectra on the basis of the known spin-Hamiltonian of orthorhombic symmetry has been provided. Models of new iron centers have been proposed, and ranges of alteration of parameters of the corresponding spin-Hamiltonians have been established. The question of the influence of the doping method (either by synthesis or by ion implantation) on the formation of different paramagnetic sites of Fe 2+ and Fe 3+ in glasses has been discussed.

Optical constants of germanium sulphide single crystal by interference method

The refractive index, n, of a GeS single crystal was measured by the interference method in the transparency region. An effective thickness smaller than the true one was introduced to account for the scattering by the layer structure of the material in this region. The effective thickness hypothesis gave a satisfactory explanation of the pronounced rise in reflectance for E < E g. The extinction coefficient, k, was calculated from the measured absorption coefficient. Measurements were performed at room temperature using plane polarized light with the plane of polarization parallel to the a- and b-crystallographic axes which lie in the plane of cleavage. The real and imaginary parts of the complex dielectric constant (ϵ r, ϵ i) as well as the reflectance and its phase change ( R, Φ) were calculated from the values of n and k. It was shown that the GeS single crystal exhibits birefringence. Assuming that GeS binding is partly ionic and partly covalent, the optical constants were satisfactorily fitted to the model of single effective oscillator.

Synthèse et activité radioprotectrice de germatranes, silatranes, oxydes et sulfures germaniés à ligande chlorhydrate de cystéamine, méthylcystéamine et N(thio-2 éthyl)diamino-1,3 propane

New organogermatranes and silatranes, germanium oxides and sulfides with cysteamine, methylcysteamine and N-(2-thioethyl)-1,3 diaminopropane chlorhydrate ligands were synthesized. Their toxicities and their radioprotective activities were determined. Germatranes were the most active in the latter category. The toxicity of all derivatives (including silatranes) was generally low.

A comparative study of silver photodoping in chalcogenide films by means of extended X-ray absorption fine structure and kinetics measurements

The photodoping of silver into amorphous germanium sulphide films under the action of UV, but not visible, radiation is reported. It is noted that the photodoping rate of silver into GeS 2 is negligible below 360 nm; thus it holds promise as a possible high resolution UV resist insensitive to visible light. The kinetics of the photodoping reaction have been studied in situ by means of resistance measurements. It is found that, unlike GeSe 2, the photodoping of GeS 2 exhibits no clear induction period; also, the rate of photodoping of GeS 2 shows a linear dependence on light intensity Φ, in contrast to the sublinear Φ 0.8 dependence found with GeSe 2. Thus it is clear that, although superficially similar, the two photodoping reactions must have significantly different mechanisms. An examination of the silver environment of photodoped and thermally doped germanium selenide by extended X-ray absorption fine structure analysis shows a first shell of selenium atoms at a distance of 2.62 Å, with a silver coordination number of from three to four; indicating that the silver atoms occupy sites covalently bonded to neighbouring selenium atoms.

New lithium ionic conductor, Li−Ge−Se glasses

Selenide glasses containing lithium were obtained at mixing compositions of 0.4Li2Se–0.6GeSe2 and 0.3Li2Se–0.54GeSe2−0.1LiI. Ionic conductivities were measured in a temperature range between −30 and 100°C by a complex-impedance method. The ionic conductivity of 0.4Li2Se–0.6GeSe2 glass is 1.8×10−5 ( cm)−1 at 25°C and the electronic contribution is less than 1%. The value of activation energy is smaller than the value for the germanium sulfide glass containing the same amount of lithium. The conductivity is enhanced by additions of LiI. The glass having composition of 0.36Li2Se–0.54GeSe2–0.1 LiI shows a conductivity of 2.5×10−5 ( cm)−1 at 25°C. Cell performance was investigated on TiS2/Li batteries using the 0.4Li2Se–0.6GeSe2 glass as solid electrolyte.

Morphological structure of bismuth-doped n-type amorphous germanium sulphide semiconductors

Recent observation of n-type conduction in amorphous Ge20Ss_xBix at large bismuth concentrations (x = 11), which otherwise shows p-type conduction, has aroused considerable interest in the international scientific community [1]. The mechanism of such impurity incorporation in a germanium chalcogenide glass is not understood and is a topic of current interest. In our recent publications [2-10] we have brought to light some hitherto unknown and interesting features of bismuth dopants in chalcogen-rich Ge-X (X -- S, Se) glassy compositions. In this communication we present our new results of investigations on vitreous semiconductors Ge20S80 Bi using electron microscopy, electron diffraction of as-prepared and annealed/pressure quenched compositions. Our results provide conclusive support to the formation of composite clusters containing all the three elements, germanium, sulphur and bismuth, which crystallize in simpler stoichiometric compounds Bi2S3 and GeS2.

Verres du systeme La 2S 3La 2O 3Ga 2O 3Ga 2S 3

The extent of the glass forming region is described as a function of the composition and of the cooling speed. The shape of this region is explained from the previously described La 2S 3La 2O 3Ga 2O 3Ga 2S 3 phase diagram. Glasses are obtained after relatively slow cooling (5°/min), in a definite region of compositions, which coincides with a relatively large concentration of ternary invariants. The thermal properties (transition temperatures and crystallization temperatures) were measured by DTA. For a relatively large region of compositions, glasses return to the equilibrium conditions with intermediate formation of the La 3.33Ga 6S 12O 2 metastable crystalline phase. An approach to the structure of the glasses is made by comparison with the crystal structures of the numerous ternary and quaternary crystalline compounds observed in the system, and by the comparison of the Raman spectra. It appears that these gallium oxysulfide glasses have many structural analogies with germanium sulfide glasses.

Electron spectroscopy and diffraction studies of metal contact reactions in amorphous chalcogenides

Structural and compositional changes occur when copper and silver films are in contact with amorphous chalcogenide films. These contact reactions have been investigated in films of four amorphous chalcogenides, arsenic trisulphide, arsenic triselenide, germanium sulphide and germanium selenide. The composition of these films has been studied by energy dispersive X-ray microanalysis and electron spectroscopy. Structural studies have been made by electron diffraction. For each chalcogenide film a structural change was observed on contact with either a copper or a silver film. At low metal concentration this structural change occurs in the amorphous phase. Depth profile studies using Auger electron spectroscopy indicate that interdiffusion of the chalcogenide and metal atoms occurs at room temperature. This interdiffusion is found to be most extensive for arsenic triselenide in contact with copper and silver films.

Electron spectroscopy and diffraction studies of metal contact reactions in amorphous chalcogenides

Abstract Structural and compositional changes occur when copper and silver films are in contact with amorphous chalcogenide films. These contact reactions have been investigated in films of four amorphous chalcogenides, arsenic trisulphide, arsenic triselenide, germanium sulphide and germanium selenide. The composition of these films has been studied by energy dispersive X-ray microanalysis and electron spectroscopy. Structural studies have been made by electron diffraction. For each chalcogenide film a structural change was observed on contact with either a copper or a silver film. At low metal concentration this structural change occurs in the amorphous phase. Depth profile studies using Auger electron spectroscopy indicate that interdiffusion of the chalcogenide and metal atoms occurs at room temperature. This interdiffusion is found to be most extensive for arsenic triselenide in contact with copper and silver films.

Pressure-induced structural transformations in Bi-doped amorphous germanium sulfide.

The problem of $n$-type doping of amorphous germanium chalcogenides is tackled by applying a Bridgman anvil technique of high pressure. A study of Bi-doped ${\mathrm{Ge}}_{20}{\mathrm{S}}_{80\ensuremath{-}x}{\mathrm{Bi}}_{x}$ and ${({\mathrm{Ge}}_{42}{\mathrm{S}}_{58})}_{100\ensuremath{-}x}{\mathrm{Bi}}_{x}$ has been made up to a pressure of 100 kbar for the first time. The appearance of two pressure-induced sharp structural transitions in ${\mathrm{Ge}}_{20}{\mathrm{S}}_{80\ensuremath{-}x}{\mathrm{Bi}}_{x}$ and one continuous transition in ${({\mathrm{Ge}}_{42}{\mathrm{S}}_{58})}_{100\ensuremath{-}x}{\mathrm{Bi}}_{x}$ is observed. X-ray diffraction and differential thermal analysis of semiconductors (as prepared and pressure quenched) reveal the presence of two pressure-induced crystalline phases ${\mathrm{Bi}}_{2}$${\mathrm{S}}_{3}$ and Ge${\mathrm{S}}_{2}$. Such structural changes in the doped semiconductors may be the contributory factor in the $n$-type doping of the chalcogenide glass.

Molekülabsorptionsspektrometrie bei elektrothermischer verdampfung in einer graphitrohrküvette : Teil 8. Untersuchung der GeS-Molekülabsorption und Bestimmung von S-Species durch Lichtabsorption von GeS-Molekülen

(Molecular absorption spectrometry with electrothermal volatilization in a graphite tube. Part 8. A study of molecular absorption of GeS and determination of sulphur species via GeS) The molecular absorption of germanium sulphide, generated by volatilization in a graphite tube, is described. The absorption bands of the D-system at 285 nm are identified and a new band at 215.2 nm is described. The conditions of the determination of sulphur-containing ions (sulphate, sulphide, sulphite, thiocyanate) are optimized. Sulphite and sulphate can be determined in the same solution by variation of the pH. The influence of other ions on the GeS absorption is discussed. The reciprocal sensitivity for a 60-μl sample giving 0.01 absorbance is 5 × 10 −5 M sulphate.

Electric conduction in n-type germanium and cadmium sulfide

The impurity conduction of n-type Ge and CdS is calculated via a previously developed theory for impurity bands in doped semiconductors. Rough agreement with experimental data over a wide range of impurity concentration is found. The comparison with AMO-MT calculation shows a large enhancement due to a stronger electron correlation.

Sulfide glass fibers for infrared transmission

Germanium sulfide glasses were drawn into fibers with optical losses lower than 1 dB/m. The glass fibers were coated with Teflon FEP or silicone resin according to their thermal properties. Loss increase caused by coating was not observed. The main problems in obtaining low-loss fibers were investigated. Sulphur evolution in fiber drawing was avoided by choosing the appropriate glass compositions and drawing conditions, OH and SH impurities were reduced to 1 4 of initial values using the S 2Cl 2 chemical reaction with water at 400–600°C. The possibility of ultra-low loss fibers using sulfide glasses is discussed in terms of intrinsic losses and impurity-related absorption losses.

ChemInform Abstract: PHYSICOCHEMICAL PROPERTIES OF SEMICONDUCTORS IN THE SYSTEM GERMANIUM SULFIDE SELENIDE (GESXSE1‐X)

Chemischer InformationsdienstVolume 10, Issue 19 Physical Inorganic Chemistry ChemInform Abstract: PHYSICOCHEMICAL PROPERTIES OF SEMICONDUCTORS IN THE SYSTEM GERMANIUM SULFIDE SELENIDE (GESXSE1-X) N. C. MARCHEVA, N. C. MARCHEVASearch for more papers by this author N. C. MARCHEVA, N. C. MARCHEVASearch for more papers by this author First published: May 8, 1979 https://doi.org/10.1002/chin.197919008AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume10, Issue19May 8, 1979 RelatedInformation

ChemInform Abstract: CRYSTALLIZATION OF AMORPHOUS GERMANIUM SULFIDE AND GERMANIUM SELENIDE UNDER PRESSURE

Chemischer InformationsdienstVolume 8, Issue 45 Physical Inorganic Chemistry ChemInform Abstract: CRYSTALLIZATION OF AMORPHOUS GERMANIUM SULFIDE AND GERMANIUM SELENIDE UNDER PRESSURE M. SHIMADA, M. SHIMADASearch for more papers by this authorF. DACHILLE, F. DACHILLESearch for more papers by this author M. SHIMADA, M. SHIMADASearch for more papers by this authorF. DACHILLE, F. DACHILLESearch for more papers by this author First published: November 8, 1977 https://doi.org/10.1002/chin.197745012Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume8, Issue45November 8, 1977 RelatedInformation