- Chlorine evolution during the fusion of chlorofluoroindate glasses
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Samples with a composition of 40InF3-20ZnF2-5MCl- xBaF2-ySrF2, where M=Na, Li and x+y=35 mol%, were prepared. The thermal properties related to the Ba/Sr ratio and to the remaining chlorine content in the glasses were studied. Thermal stability is improved with the addition of chlorine. However, chlorine concentration is regulated by the sublimation of indium fluorides which takes place at about 600°C. Indium fluorides arc formed during glass fusion. The mechanisms of chlorine sublimation were studied.
- Delben,Rojas,Miazato,Melnikov,Delben,Cardoso,Job
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- Novel fabrication process of planar waveguides in rare-earth doped fluoroindate glasses
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A method to fabricate planar waveguides in rare-earth doped fluoroindate glasses has been developed. This method of preparing waveguides in this kind of glass opens new prospects in fluoroindate glass research and development. The potential of these waveguides for devices operating in the communications wavelengths is anticipated to be very promising since the rare-earth doped fluoroindate glass exhibits small nonradiative relaxation rates for the rare-earth ions.
- Melo, R. P. de Jr.,Silva, B. J. P. da,Falcao-Filho, E. L.,Silva, E. F. da Jr.,Petrov, D. V.,et al.
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- Infrared-to-visible CW frequency upconversion in Er3+-doped fluoroindate glasses
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An effective CW pumped infrared-to-visible upconversion in Er3+-doped fluoroindate glass is demonstrated. InF3 is obtained by fluoration in In2O3 at 400°C with NH4H and HF in a platinum crucible. All fluoride components are then mixed and heated in a dry box under argon atmosphere at 700°C for melting and 800°C for finning. Next, the melt is poured and cooled into a preheated brass mold. Continuous-wave upconversion fluorescence measurements are performed using a diode laser emitting at 1.48μm as the excitation source.
- de Araujo,Menezes,Maciel,Acioli,Gomes,Messaddeq,Florez,Aegerter
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- The crystal structure of the weberite Na2MgInF7
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The fluoride Na2MgInF7 is orthorhombic: a = 10.435(1) A, b = 7.345(1) A, c = 7.553(1) A, Z = 4. Its crystal structure was solved in the space group Pnma (No. 62), from X-ray single crystal data using 1879 unique reflections (1183 with Fo/σ(Fo)>4). The three-dimensional network is built up from tilted chains of trans corner-sharing [MgF6] octahedra running along the shortest axis of the cell. These chains are linked together through four corners of [InF6] octahedra. The sodium ions are 8 and 7 coordinated to fluorine. The [NaF8] polyhedron can be described as a distorted cube, whereas the [NaF7] polyhedron is a pentagonal bipyramid. Despite a different space group, the crystal structure of Na2MgInF7 can be easily related to the orthorhombic body-centered weberite-type structure.
- Caramanian, Armen,Souron, Jean-Paul,Gredin, Patrick,De Kozak, Ariel
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- Distribution coefficients of impurities in cadmium fluoride
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Experimental data on the liquidus curve in cadmium fluoride-metal fluoride systems were used to calculate the distribution coefficients of di- and trivalent impurities in CdF2. A similar method was proposed for calculating the distribution coefficient from solidus data. It was shown that the variations of the calculated distribution coefficients with the ionic radii of M2+ and R3+ are well fitted by Gaussians. Phase relations in the CdF2-rich part of the CdF2-InF3 system were studied by differential thermal analysis and x-ray diffraction.
- Ivanov,Buchinskaya,Fedorov
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- Structure and thermal stability of novel fluorophosphate glasses
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A systematic investigation on glass formation in the PbF 2-InF3-BaHPO4 ternary system has been carried out. These glasses have characterized by IR spectra, Raman spectra and differential thermal analysis. The results show that the structure of these glasses is mainly affected by BaHPO4 and InF3 contents. With decreasing BaHPO4 content, the glass structure gradually transforms from metaphosphate to polyphosphate. When InF3 content is low, it mainly acts as network modifier, when its content is high; it enters glass matrix and forms In(O,F)6 groups connecting the polymerized phosphorus oxygen species. PbF2 mainly acts as network modifier in this system. Systematic variations of the glass transition temperature and the thermal stability index agree well with these results. The most stable glass with ΔT = 230 °C and S = 21.79 K is obtained.
- Sun, Hongtao,Zhang, Liyan,Xu, Shiqing,Dai, Shixun,Zhang, Junjie,Hu, Lili,Jiang, Zhonghong
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- Optical properties of chromium-doped fluoroindate glasses
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This work reports on the optical properties of Cr3+ ions in the pseudoternary system InF3-GdF3-GaF3. Linear properties, investigated through absorption and emission spectra, provide information on the crystal field, the frequency, and number of phonons emitted during the absorption to the 4T2 band and the emission to the 4A2 ground state, and the Fano antiresonance line shape in the vicinity of the 4A2→2E transition. A study of the nonlinear refractive index as a function of the wavelength, carried out with the Z-scan technique, provides spectroscopic data about electronic transitions starting from the excited state.
- Mendonca,Costa,Messaddeq,Zilio
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- Frequency upconversion in Er3+-doped fluoroindate glasses pumped at 1.48 μm
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We report on efficient frequency upconversion in Er3+-doped fluoroindate glass. The process is observed under 1.48 μm laser diode excitation and results in fluorescence generation in the range from ultraviolet to near-infrared radiation. The study was performed for samples containing 1, 2, and 3 ErF3 mol % in the range of temperatures from 24 to 448 K. The upconverted signals were studied as a function of the laser intensity, and their dynamical behavior is described using a rate equation model which allows us to obtain the energy transfer rates between Er3+ ions in pairs and triads.
- Maciel,De Araujo, Cid B.,Messaddeq,Aegerter
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- Quantum-chemical calculations and IR spectra of the (F2)MF 2 molecules (M = B, Al, Ga, In, Tl) in solid matrices: A new class of very high electron affinity neutral molecules
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Electron-deficient group 13 metals react with F2 to give the compounds MF2 (M = B, Al, Ga, In, Tl), which combine with F 2 to form a new class of very high electron affinity neutral molecules, (F2)MF2, in solid argon and neon. These (F 2)MF2 fluorine metal difluoride molecules were identified through matrix IR spectra containing new antisymmetric and symmetric M-F stretching modes. The assignments were confirmed through close comparisons with frequency calculations using DFT methods, which were calibrated against the MF3 molecules observed in all of the spectra. Electron affinities calculated at the CCSD(T) level fall between 7.0 and 7.8 eV, which are in the range of the highest known electron affinities.
- Wang, Xuefeng,Andrews, Lester
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p. 3768 - 3771
(2011/04/26)
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- Preparation and characterization of high-purity metal fluorides for photonic applications
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We combine chelate-assisted solvent extraction (CASE) and hot hydrogen fluoride gas treatment to enable a general method for the preparation of high-purity binary metal fluorides. The fluorozirconate glass ZBLANI:Yb 3+ (ZrF4-BaF2-LaF3-AlF 3-NaF-InF3-YbF3), a solid-state laser-cooling material, is used as a test case to quantitatively assess the effectiveness of the purification method. The reduction of transition-metal and oxygen-based impurities is quantified directly by inductively coupled plasma mass spectrometry (ICP-MS) and indirectly by laser-induced cooling, respectively. The concentrations of Cu, Fe, Co, Ni, V, Cr, Mn, and Zn impurities in the ZrCl 2O precursor solution were measured individually by ICP-MS at various stages of the purification process. CASE was found to reduce the total transition-metal concentration from 72500 to ～100 ppb. Laser cooling was most efficient in ZBLANI:Yb3+ glass fabricated from CASE-purified metal fluoride precursors, confirming the results of the ICP-MS analysis and demonstrating the effectiveness of the purification methods in a finished optical material. High-purity metal fluorides prepared by the methods presented herein will enable new high-performance optical materials for solid-state optical refrigerators, crystals for vacuum ultraviolet (VUV) spectroscopy of the Thorium-229 nucleus, VUV optics, fibers, and thin-film coatings.
- Patterson, Wendy M.,Stark, Peter C.,Yoshida, Thomas M.,Sheik-Bahae, Mansoor,Hehlen, Markus P.
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p. 2896 - 2901
(2011/12/22)
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- Spectroscopic characterization of Ho3+ ion-doped fluoride glass
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Among the new optical materials available, fluoride glass, which has an extended transmission window, is emerging as an important material for use in optical fibers, lasers, sensors, etc. Here, we analyze the spectroscopic properties of Ho3+ ions in a fluoroindate glass based on absorption measurements. Ho3+-doped fluoroindate glass with the composition (40 - x)InF3-20SrF2-20ZnF2-16BaF2-2GdF3-2NaF-xHoF3, x = 1.0, 2.0, 2.5, 3.0, 4.0, 5.0, 6.0, 8.0 and 9.0 mol%, was prepared under an argon atmosphere. Absorption spectra in the range 300-2200 nm were then obtained. The experimental oscillator strength fExp. was calculated from the areas under absorption bands. Using Judd-Ofelt theory and least-squares fitting, the phenomenological intensity parameter Ωλ (λ = 2, 4, 6) and the theoretical oscillator strength fCal. were calculated. To evaluate potential applications and to analyze the properties of Ho3+ ions in these host glasses, the following spectroscopy parameters were calculated: the transition probability between multiplets AJJ′, the branching ratio βJJ′, the radiative lifetime τR, the peak cross-section for stimulated emission σp, and the emitting-level multiphonon rate WNR for each band. The results were compared with those reported in the literature for similar glasses of the same concentration.
- Florez,Oliveira,Flórez,Gómez,Nunes
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p. 238 - 242
(2008/10/09)
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- Indium(I) hexafluoropnictates (InPnF6; Pn = P, As, Sb)
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The colourless compounds InPnF6 (Pn = P, As, Sb), with In I in a solely fluorine environment, were prepared by reacting In metal with PnF5 (Pn = P) and displacement of the weaker Lewis acid BF3 from InBF4 by a stronger one, PnF5 (Pn = As, Sb), in anhydrous hydrogen fluoride (aHF). The X-ray powder diffraction analyses show that InPF6 crystallises in cubic unit cell with a = 8.07(2) A, while InAsF6 crystallises in a rhombohedral unit cell with a = 7.58(2) and c = 7.90(1) A. The Raman spectra of InPnF 6 (Pn = P, As, Sb) confirm the formation of PnF6 - salts. An attempt to prepare InF and In2F4 (InIInIIIF4) by reaction of CsF with InSbF 6 in aHF or by metathetical reaction of InSbF6 with CsInF4 in aHF, respectively, failed. Instead of InF and In 2F4, respectively, a mixture of In and InF3 was obtained. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.
- Mazej, Zoran
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p. 3983 - 3987
(2007/10/03)
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- The crystal structure of Kx(MgxIn1-x)F3 (x = 0.38): A new magnéli-bronze type fluoride
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Kx(MgxIn1-x)F3 (x = 0.38) is monoclinic, pseudo tetragonal: a = 12.781(2) ?, b = 12.787(2) ?, c = 7.930(1) ?, β = 90,00(1)°, Z = 20. The crystal structure was solved in the space group P21/a (No. 14), subgroup of the tetragonal space group P4/mbm (No. 127), from X-ray single crystal data using 4302 unique reflections (1770 with Fo/σ(Fo) > 4). The final observed R factor is 0.053. Kx(MgxIn1-x)F3 has the Magnéli-bronze structural type, which consists in a tridimensional framework of mixed [(MgxIn1-x)F6] octahedra linked together by corners. The potassium ions are mainly located in large almost fully occupied 15-coordinated sites and in practically empty 12-coordinated cavities.
- Caramanian, Armen,Dupont, Nathalie,Gredin, Patrick,De Kozak, Ariel
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p. 933 - 938
(2008/10/08)
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- Slow Hydration of Indium Trifluoride
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Conversion of powdered InF3 over a 10-year storage in air is investigated. Successive formation of an intermediate phase and trihydrate InF3 · 3H2O is revealed by X-ray diffraction analysis. The formation of InOHF2 indicates that hydrolysis, though extremely slow, takes place even at room temperature.
- Fedorov,Bondareva,Stasyuk,Sobolev,Skorokhvatov,Fedorov
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p. 618 - 619
(2008/10/08)
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- Blue and green upconversion in Er3+-doped fluoroindate glasses
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The upconversion properties of Er3+ in fluoroindate bulk glasses (composition: 40InF3-20ZnF2-16BaF2-(20-x) SrF2-2GaF3-2NaF-xErF3 with x=1, 2, 3, and 4 mole %) are investigated, following 4F9/2 excitation with a red krypton laser. A strong green and a weaker blue luminescence is observed at room temperature corresponding to emissions from the thermally coupled 4S3/2 and 2H11/2 bands and the 2H9/2 level respectively. Resonant energy transfer processes involving two excited erbium ions and a two-step absorption process are proposed to explain the upconversion phenomena. The emission intensities depend on the excitation power as Pexcn with 1.5 ≤n≤1.7 for the green and 1.6 ≤n≤1.9 for the blue emission. The decay times and the relative intensities of the luminescences are also studied as a function of Er3+ concentration.
- Reiche,Nunes,Carvalho,Messaddeq,Aagerter
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p. 773 - 777
(2008/10/08)
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- Crystal structure of the metastable form of aluminum trifluoride β-AlF3 and the gallium and indium homologs
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The crystal structure of the metastable phase β-AlF3, which is related to the hexagonal tungsten bronze structure, has been solved by X-ray powder and single-crystal diffraction methods. The crystal habit is pseudo-hexagonal with systematic twinning (rotation of 120° around the c axis), but the true symmetry is orthorhombic. The network is built from very regular AlF6 octahedra rotated by approximately 7.2° from the positions of the ideal HTB structure. A similar network, with the same propagation of the tilting, was observed in the compound (H2O)0.33FeF3 and in the metastable polymorphs of CrF3 and of VF3.
- Bail, A. le,Jacoboni, C.,Leblanc, M.,Pape, R. de,Duroy, H.,Fourquet, J. L.
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- NEW OXYFLUORIDES CONTAINING INDIUM WITH POTENTIAL FERROELASTIC PROPERTIES.
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X-ray diffraction, micro-DTA, and microcalorimetric measurements have been performed on compounds of the InF//3-TiOF//2, InF//3-MO//2F (M equals Nb, Ta), and InF//3-WO//3 systems. Extended domains of solid solutions exhibiting ReO//3-related structures have been detected. Phase transitions of a ferroelastic-prototype nature have been pointed out. In the latter system several domains have been identified, connected with the various allotropic forms of WO//3. The variation of the transition temperatures with composition has been determined. They decrease when indium is substituted to tungsten simultaneously with fluorine to oxygen.
- Grannec, J.,Yacoubi, A.,Ravez, J.,Hagenmuller, P.
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p. 263 - 269
(2008/10/08)
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