Artykuły w czasopismach: „Dielectric Spectra - Glass Network Structure”

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Xu, Xing Jun, Yun Long Yue, Hai Tao Zhang i Zhao Du. "Effect of MgO on Structure and Properties of CaO-Al₂O₃-SiO₂ Glass System". Advanced Materials Research 306-307 (sierpień 2011): 531–34. http://dx.doi.org/10.4028/www.scientific.net/amr.306-307.531.

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CaO-Al2O3-SiO2system glasses with MgO were prepared by melt quenching. The glass structure was characterized by Infrared spectra (IR) and Differential Thermal Analysis (DTA). Dielectric properties, devitrification and chemical durability have been studied. IR spectra and DTA indicated that glass network structure change by doping MgO. The glass chemical improved and dielectric constant decreased after doping with MgO. The glass shows a severe tendency of phase separation.

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Rani, S., S. Sanghi, A. Agarwal i N. Kishore. "Study of Structure and Li⁺ Ions Dynamics in Presence of Fe₂O₃ in Bi₂O₃∙B₂O₃ Glasses". Solid State Phenomena 161 (czerwiec 2010): 51–61. http://dx.doi.org/10.4028/www.scientific.net/ssp.161.51.

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Glasses having composition xLi2O∙(30-x)Fe2O3∙20Bi2O3∙50B2O3 (0 ≤ x ≤ 30, in mol%) have been prepared using normal melt-quench technique. The variation in density and molar volume with composition has been investigated in terms of the structural modification that takes place in the glass matrix on decreasing Fe2O3. Infrared spectra of these glasses were recorded over continuous spectral range (400-4000 cm-1) in an attempt to study their structure systematically. IR spectra show that with increase in Li2O/Fe2O3 ratio there is formation of more structural units (e.g. [FeO4/2]-Li+) in the glass network. Bi3+ cations are present as [BiO6] octahedral units and acts as modifier in this glass system. Further, the effect of transition metal ions (iron) on the dynamics of lithium bismuth borate glasses has been studied in the frequency range of 20 Hz - 1 MHz and in the temperature range 240 – 350 °C using impedance spectroscopy. Possible conduction mechanisms are discussed. Various AC and DC electrical and dielectric parameters have been calculated and analyzed. The results show that the contribution of electronic conduction towards conductivity decreases with decreasing iron concentration, which is understood to be due to hopping of electrons from Fe2+→Fe3+. The frequency dependent conductivity has been studied using both conductivity and modulus formalism. The absence of maximum observed in dielectric permittivity in the temperature and frequency range studied, indicate the non-ferroelectric behavior of the glasses.

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Modak, D. K., G. Banerjee, M. Karar, M. Sadhukhan, A. K. Bera, B. K. Chaudhuri i P. K. Pal. "Nonlinear physical properties of some nonconventional semiconducting Bi–Pb–Ba–O glasses". Journal of Materials Research 13, nr 8 (sierpień 1998): 2328–33. http://dx.doi.org/10.1557/jmr.1998.0325.

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Semiconducting Bi1−xPbxBaO3−δ (or BPB) glasses with x = 0 to 0.8 have been prepared by fast quenching from the melt. Interesting anomalies in the temperature-dependent polaronic conductivity and dielectric constant have been observed in all these glass compositions at temperatures, Tp, varying from 310 to 330 K (depending on Pb concentration). This nonlinear behavior is considered to be associated with the local ordering or the displacements of the BiO3 type pyramidal structural units present in the glass matrix (observed from the infrared spectra of these glasses). This type of ordering/displacement gives rise to a local instability in the glass network structure which is also supported by the observed heat capacity anomaly around the same temperatures Tp.

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Yan, Hong Qiang, Hua Qing Wang, Jie Cheng i Zheng Ping Fang. "Cure of Neat Resins and Properties of Composites for Interpenetrating Polymer Networks from the Novel Bismaleimide and Cyanate Containing Naphthalene". Advanced Materials Research 233-235 (maj 2011): 1636–41. http://dx.doi.org/10.4028/www.scientific.net/amr.233-235.1636.

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To obtain attractive properties, such as increased resistance to moisture absorption, low dielectric constant and low dielectric loss, the novel bismaleimide, viz. 2,7-bis(4-maleimidophenoxy) naphthalene (BMPN), and dicyanate ester, viz. 2,7-dihydroxynaphthalene dicyanate (DNCY), containing naphthalene ring and ether linkages, have been synthesized. The cure process of the blends including of 0.11mmol/mol Fe(AcAc)3 and 2% nonylphenol is characterized by in-situ FTIR. The result obtained from in-situ FTIR spectra of cured resin illuminates that the cure reaction is homo-polymerized respectively at this condition for the mixtures of B1C1. Interlaced network patterns are seen obviously and no visible phase separation could be detected in the region for IPNs BT resin by SEM. The structure of IPNs can be formed for the blends of BMPN and DNCY containing 0.11 mmol/mol Fe(AcAc)3 and 2% nonylphenol, which is tested by in-situ FTIR and SEM methods. The glass fiber reinforced composites for this blends are made and their properties are studied. This composites show good flexural property, low dielectric constants ( Dk ) and low moisture absorption.

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Basu, S., J. R. Macdonald i D. Chakravorty. "Conductivity relaxation in the interfacial phase of iron core–iron oxide shell nanocomposites". Journal of Materials Research 21, nr 7 (1.07.2006): 1704–11. http://dx.doi.org/10.1557/jmr.2006.0231.

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The alternating current electrical conductivity of a gel-derived glass of composition 55Fe2O3⋅45SiO2 (mol%) was measured over a frequency range of 100 Hz to 6 MHz. The gel was subjected to a reduction treatment at 923 K for ½ h and subsequently heated in ordinary atmosphere at a temperature 773 K for ½ h to grow a Fe-core Fe3O4 shell nanostructure with a median diameter of 6.2 nm. This formed a percolative network within the silica gel. Mossbauer spectra confirmed the presence of Fe3O4 in the nanoshell. Electrical measurements were also carried out on these nanocomposites at different frequencies and temperatures. Isothermal electrical modulus data for both reference and treated glass systems were analyzed using both the CK0 and CK1 Kohlrausch-related frequency response models. Reference-glass shape parameter values, estimated by fitting the experimental data to the K0 model at several temperatures, were found to be ∼0.32. Here, the K0 model led to much better fits than the K1 did. However, for the treated core–shell-structured nanocomposite material, both models yielded good fits with consistent but different shape parameter estimates: very close to ½ for the K0 model and ⅓ for the K1 model. In accordance with the structural measurements and with axiomatic topological considerations that predict a shape-parameter value of ⅓ for one-dimensional motion and ½ for two-dimensional motion, it appears that the ∼0.32 value is consistent with one-dimensional motion of charge carriers along the narrow channels of the interconnected iron-rich three-dimensional phase of the reference glass. Further, although the K1-model ⅓ estimates for the treated material also indicate the presence of one-dimensional charge motion at the two-dimensional interface between the two interconnected phases of the reference glass, the ½ K0 estimates for the same material suggest an effective charge-motion dimension of 2. Importantly, comparison of the high-frequency dielectric constant estimates for the K0 reference glass and the K1 treated one clearly leads to the new but physically plausible conclusion that the bulk frequency-independent dielectric constant of about 30 is independent of the treatment.

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Singh, N. L., Chaitali Gavade i P. K. Khanna. "Swift Heavy Ion Induced Modification in Physical Properties of Poly Methylmethacrylate (PMMA)/Nickel (Ni) Nanocomposites". Defect and Diffusion Forum 341 (lipiec 2013): 51–68. http://dx.doi.org/10.4028/www.scientific.net/ddf.341.51.

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We have These films were irradiated with 85 MeV C-ions at the fluences of 1 x 1011 and 1 x 1012 ions/cm2. Changes in the optical, structural, dielectric, magnetic and thermal properties of (PMMA)/Ni nanocomposites of different concentrations of nickel nanoparticles (5%, 10%, 15%) due to swift heavy ion irradiation were studied by means of UVvisible spectroscopy, X-ray diffraction, impedance gain phase analyzer, SQUID and differential scanning calorimetry. Optical properties like band gap were estimated for pure polymer and nanocomposite films from their optical absorption spectra in the wavelength range 200-800 nm. It was found that the band gap value shifted to lower energy on doping with metal nanoparticles. Differential scanning calorimetry analysis revealed a decrease in the glass transition temperature upon irradiation, which may be attributed to the scissioning of polymer chain due to ion beam irradiation which is also corroborated with XRD analysis. Surface morphology of the pristine and irradiated films was studied by scanning electron microscopy (SEM). The breakage of chemical bonds resulted in an increase of free radicals, unsaturation etc. as revealed from FTIR analysis. The dielectric properties were observed to enhance with an increase in metal compound concentration as well as with irradiation dose. This may be due to metal/polymer bonding and conversion of polymeric structure into hydrogen-depleted carbon network. Zero-Field-Cooled (ZFC)/Field-Cooled (FC) magnetization and magnetic hysteresis measurements were performed using a superconducting quantum interference device (SQUID) magnetometer from temperatures ranging from 5 K to 300 K, to investigate the magnetic properties of nanocomposites. The changes in topography of surfaces were also observed upon irradiation.

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Yuan, X. M., S. M. Lu, X. H. Zhang, Y. J. Cui, H. T. Wu i Y. L. Yue. "Effects of CaO Additions on the Structure and Dielectric Properties of Aluminoborosilicate Glasses". Advanced Materials Research 710 (czerwiec 2013): 127–31. http://dx.doi.org/10.4028/www.scientific.net/amr.710.127.

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Glasses with compositions xCaO-(60-x)SiO2-5MgO-15Al2O3-20B2O3 (x=0, 3, 6 and 9 mol %) were prepared by conventional melting method. Fourier-transform infrared spectroscopy (FTIR) indicated that the addition of CaO converted trigonal boron ([B) to tetrahedral boron ([B). The glass transition temperatures (Tg) were determined using a differential scanning calorimetry (DSC). Tg increased with increasing CaO content. Thus, the addition of CaO instead of SiO2 strengthened the glass network. The dielectric εr and loss tanδ were measured for the MgO-B2O3-Al2O3-SiO2 glass system in the frequency range 103-105 Hz. The decrease in εr and tanδ could be attributed to the increase in the rigidity of the glass network.

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Shao, Hui, Hong Qing Zhou i Xiao Dong Shen. "The Influence of B₂O₃ on the Microstructures and Properties of CaO-B₂O₃-SiO₂-Al₂O₃ Glass-Ceramics (α-Al₂O₃) System". Advanced Materials Research 189-193 (luty 2011): 4466–71. http://dx.doi.org/10.4028/www.scientific.net/amr.189-193.4466.

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The glass composition CaO-Al2O3-B2O3-SiO2 as an alternative glass composition, and commercial α-Al2O3 as a ceramic material was used. The structure of the glass was analyzed by infrared spectra; the glass-ceramics thermal expansion coefficient was measured by dilatometer, the phase separation of the sample was investigated by scanning electron microscope and the component of phase was analyzed by X-ray. The results show that [BO3] increases and [BO4] decreases in the glass structure with the increasing of B2O3 content added into CaO-Al2O3-B2O3-SiO2 glass. The relative density and dielectric constant (εr) are considerably decreased with the addition of amount of B2O3. Excellent microwave dielectric properties of 1MHz, εr = 8.0 and tanδ=0.003 are obtained by adding 10 wt% B2O3 to glass-ceramic and sintering at 875°Cfor 30 min.

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DU, ZHAO, XUEHONG ZHANG, YUNLONG YUE i HAITAO WU. "EFFECT OF MgO ON STRUCTURE AND DIELECTRIC PROPERTIES OF CaO–Al2O3–B2O3–SiO2 GLASSES". Surface Review and Letters 19, nr 06 (27.11.2012): 1250063. http://dx.doi.org/10.1142/s0218625x12500631.

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The effect of MgO on structure and dielectric properties of aluminoborosilicate glasses was investigated. FTIR data indicated that glass network was mainly built by tetrahedral [ SiO4 ], [ BO4 ], [ AlO4 ] and trigonal [ BO3 ]. A small amount of AlO5 or AlO6 units also existed. The glass system was characterized with lower dielectric constant (4.17 ~ 4.6) and dielectric loss (12.3 × 10-4 ~ 14.77 × 10-4) at 1 MHz. With the increase of MgO content, the quantity of AlO5 or AlO6 units decreased. The variation of density showed a decreasing tendency. The dielectric constant and loss were all found to decrease.

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Herrmann, Andreas, Mohamed Zekri, Ramzi Maalej i Christian Rüssel. "The Effect of Glass Structure on the Luminescence Spectra of Sm3+-Doped Aluminosilicate Glasses". Materials 16, nr 2 (6.01.2023): 564. http://dx.doi.org/10.3390/ma16020564.

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Peralkaline Sm3+-doped aluminosilicate glasses with different network modifier ions (Mg2+, Ca2+, Sr2+, Ba2+, Zn2+) were investigated to clarify the effect of glass composition and glass structure on the optical properties of the doped Sm3+ ions. For this purpose, the Sm3+ luminescence emission spectra were correlated with the molecular structure of the glasses derived by molecular dynamics (MD) simulations. The different network modifier ions have a clear and systematic effect on the peak area ratio of the Sm3+ emission peaks which correlates with the average rare earth site symmetry in the glasses. The highest site symmetry is found for the calcium aluminosilicate glass. Glasses with network modifier ions of lower and higher ionic radii show a notably lower average site symmetry. The symmetry could be correlated to the rare earth coordination number with oxygen atoms derived by MD simulations. A coordination number of 6 seems to offer the highest average site symmetry. Higher rare earth coordination probabilities with non-bridging oxygen result in an increased splitting of the emission peaks and a notable broadening of the peaks. The zinc containing glass seems to play a special role. The Zn2+ ions notably modify the glass structure and especially the rare earth coordination in comparison to the other network modifier ions in the other investigated glasses. The knowledge on how glass structure affects the optical properties of doped rare earth ions can be used to tailor the rare earth absorption and emission spectra for specific applications.

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Hou, Zhao Xia, Zhao Lu Xue, Shao Hong Wang, Xiao Dan Hu, Hao Ran Lu, Chang Lei Niu, Hao Wang, Cai Wang i Yin Zhou. "Thermal Stability and Structure of Tellurite Glass". Key Engineering Materials 512-515 (czerwiec 2012): 994–97. http://dx.doi.org/10.4028/www.scientific.net/kem.512-515.994.

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Oxyﬂuoride tellurite glass with the composition of TeO2-AlF3-LaF3-ZnO/ZnCl2/ZnF2 was prepared successfully. The thermal stability and structure of TeO2-AlF3-LaF3 system tellurite glass were studied bySubscript text DSC and IR spectra. The results indicated that glass transition temperature of TeO2-AlF3-LaF3-ZnO/ZnCl2/ZnF2 glass was higher than that of (1-x)TeO2-xAlF3 (x=10%, 20%, 30%, 40%, 50%, in mol%) binary glass system slightly. A small number of ZnF2/ZnCl2/ZnO (5mol%) improved glass thermal stability. After adding 5mol% ZnF2/ZnO/ZnCl2 into fluoride tellurite glass respectively, glass transition temperature increased in turn. The introduction of 5mol% different zinc compounds had a little impact on the glass network structure.

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Maximean, Doina Manaila, Octavian Danila, Pedro L. Almeida i Constantin Paul Ganea. "Electrical properties of a liquid crystal dispersed in an electrospun cellulose acetate network". Beilstein Journal of Nanotechnology 9 (15.01.2018): 155–63. http://dx.doi.org/10.3762/bjnano.9.18.

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Electro-optical devices that work in a similar fashion as PDLCs (polymer-dispersed liquid crystals), produced from cellulose acetate (CA) electrospun fibers deposited onto indium tin oxide coated glass and a nematic liquid crystal (E7), were studied. CA and the CA/liquid crystal composite were characterized by multiple investigation techniques, such as polarized optical microscopy, dielectric spectroscopy and impedance measurements. Dielectric constant and electric energy loss were studied as a function of frequency and temperature. The activation energy was evaluated and the relaxation time was obtained by fitting the spectra of the dielectric loss with the Havriliak–Negami functions. To determine the electrical characteristics of the studied samples, impedance measurements results were treated using the Cole–Cole diagram and the three-element equivalent model.

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Lu, S. M., X. M. Yuan, X. H. Zhang, Y. J. Cui, H. T. Wu i Y. L. Yue. "Effects of CeO₂ Additions on the Structure and Dielectric Properties of Aluminoborosilicate Glasses". Advanced Materials Research 710 (czerwiec 2013): 132–35. http://dx.doi.org/10.4028/www.scientific.net/amr.710.132.

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Glasses with compositions 15Al2O3-20B2O3-50SiO2-5CaO-(10-x)MgO-xCeO2 (x=0, 1, 2 and 3 mol %) were prepared by conventional melting method. Fourier-transform infrared spectroscopy (FTIR) indicated that the addition of CeO2 converted trigonal boron ([B) to tetrahedral boron ([B). The glass transition temperatures (Tg) were determined using a differential scanning calorimetry (DSC). Tg increased with increasing CeO2 content. Thus, the addition of CeO2 instead of MgO strengthened the glass network. The dielectric constant εr and loss tanδ were measured for these glasses at 105 Hz. The decrease in εr and tanδ could be attributed to the increase in the rigidity of the glass network as the CeO2 content increased.

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Montenero, A., R. A. Condrate i Y. M. Guo. "Structural information concerning the glass network in Bi–Zn–Fe–B–O glasses". Journal of Materials Research 4, nr 3 (czerwiec 1989): 473–75. http://dx.doi.org/10.1557/jmr.1989.0473.

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Fourier transform infrared (FTIR) absorption spectra were measured for various glasses in the Bi–Zn–Fe–B–O system, and interpreted upon the basis of glass structure. Spectral changes were noted with variations in the composition for these glasses that were related to changes in the atomic arrangement of the boron oxide portion of the glass network. The changes in glass transformation temperature with changes in glass composition were discussed in terms of structural data.

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Kassa, B., J. Leta Tesfaye, B. Bulcha, R. Kiran, T. Deepak, Dayanand Lal, S. Venkatesh i R. Krishnaraj. "Effect of Manganese Ions on Spectroscopic and Insulating Properties of Aluminophosphate Glasses". Advances in Materials Science and Engineering 2021 (29.06.2021): 1–11. http://dx.doi.org/10.1155/2021/6253069.

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The melt-quenching technique was used to produce 39CdO–10Al2O3-(51-x) P2O5: xMnO glasses (x = 0, 0.1, 0.2, 0.3, and 0.4 wt.%). Various stability factors were calculated and presented from DTA analysis. The stability of the glass network appears to increase with the increase of MnO concentration, according to the findings. IR spectral analysis of these glasses exhibited several symmetrical and asymmetrical bands due to phosphate groups. The observed change in these band intensities with the rise in MnO concentrations, ranging from 0.1 wt.% to 0.4 wt.%, shows an increase in the stability of the glass network. Optical absorption analyses of these glasses revealed an absorption band that shifted from 500 to 488 nm as the concentration of manganese oxide (MnO) increased from 0.1 wt.% to 0.4 wt.%, indicating that Mn2+ ions were gradually converted into Mn3+ ions. EPR spectra of these glasses were characterized by two signals due to Mn2+ and Mn3+ ions. Observations on these signal intensity variations revealed an increase in stability of the glass network with the increase of MnO concentration from 0.1 wt.% to 0.4 wt.%. Parameters, which describe the insulating characteristics, for example, dielectric constant, ε, dielectric loss, tan δ, and AC conductivity σac, were determined in relation to frequency (103 Hz to 105 Hz) and temperature (20°C to 400°C) and presented in the dielectric analysis of these glasses.

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Khodorov, Anatoli, i M. J. M. Gomes. "Optical Properties of PLZT 9/65/35 Thin Films on ITO-Coated Glass Substrate". Materials Science Forum 514-516 (maj 2006): 193–97. http://dx.doi.org/10.4028/www.scientific.net/msf.514-516.193.

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Lanthanum modified lead zirconate titanate (PLZT) thin films were fabricated on indium doped tin oxide (ITO) - coated glass substrate by sol-gel method. The structure of the films was characterized with XRD and SEM. In the case of PLZT the dielectric function was modelled as a sum of Lorentzian oscillators and found by fitting the transmittance and reflectance spectra measured at normal incidence in the wavelength range of 220-2400 nm. The anomalous behaviour of dielectric function was observed below the absorption edge that was suggested to be due to formation of some defect states. The evolution of the absorption edge as well as dielectric function with film thickness was observed and discussed.

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Haily, E., L. Bih, A. El Bouari, A. Lahmar, M. El Marssi i B. Manoun. "Effect of the Ba/K ratio on structural, dielectric and energy storage properties of BaO–K2O–TiO2–P2O5 glass-ceramics". Physics and Chemistry of Glasses: European Journal of Glass Science and Technology Part B 61, nr 6 (12.12.2020): 213–21. http://dx.doi.org/10.13036/17533562.61.6.015.

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xBaO–(20−x)K2O–30TiO2–50P2O5 with (0≤x≤20 mol%) glasses were successfully elaborated by the melt quenching while their related glass-ceramics were developed by controlled crystallisation. Density and molar volume measurements, differential thermal analysis and Raman spectroscopy were carried out to examine the glassy structure, the results revealed that the addition of BaO increases the reticulation and reinforces the glass network by the creation of strengthened linkages. X-ray diffraction has identified the formation of MTi2(PO4)3 with M=(K, Ba0·5) in all the glass-ceramics (GC) and the precipitation of a secondary BaTiP2O8 phase when x increase beyond 10 mol%. The dielectric properties of the glass-ceramics were studied by impedance spectroscopy, it showed that the addition of BaO induces an enhancement of both thermal and frequency stability of the dielectric parameters (εr and tanδ). The glass-ceramic with 5 mol% of BaO GC-(x=5) presents the highest dielectric constant and the lowest dielectric loss. The P-E hysteresis loops were recorded at room temperature and the energy storage parameters of the glass-ceramics were determined. These parameters were significantly improved by the increase of the BaO content and the optimum parameters were obtained for GC-(x=5). The dielectric and energy storage parameters were discussed according to the structure data.

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Renlund, Gary M., Svante Prochazka i Robert H. Doremus. "Silicon oxycarbide glasses: Part II. Structure and properties". Journal of Materials Research 6, nr 12 (grudzień 1991): 2723–34. http://dx.doi.org/10.1557/jmr.1991.2723.

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Silicon oxycarbide glass is formed by the pyrolysis of silicone resins and contains only silicon, oxygen, and carbon. The glass remains amorphous in x-ray diffraction to 1400 °C and shows no features in transmission electron micrographs (TEM) after heating to this temperature. After heating at higher temperature (1500–1650 °C) silicon carbide lines develop in x-ray diffraction, and fine crystalline regions of silicon carbide and graphite are found in TEM and electron diffraction. XPS shows that silicon-oxygen bonds in the glass are similar to those in amorphous and crystalline silicates; some silicons are bonded to both oxygen and carbon. Carbon is bonded to either silicon or carbon; there are no carbon-oxygen bonds in the glass. Infrared spectra are consistent with these conclusions and show silicon-oxygen and silicon-carbon vibrations, but none from carbon-oxygen bonds. 29Si-NMR shows evidence for four different bonding groups around silicon. The silicon oxycarbide structure deduced from these results is a random network of silicon-oxygen tetrahedra, with some silicons bonded to one or two carbons substituted for oxygen; these carbons are in turn tetrahedrally bonded to other silicon atoms. There are very small regions of carbon-carbon bonds only, which are not bonded in the network. This “free” carbon colors the glass black. When the glass is heated above 1400 °C this network composite rearranges in tiny regions to graphite and silicon carbide crystals. The density, coefficient of thermal expansion, hardness, elastic modulus, index of refraction, and viscosity of the silicon oxycarbide glasses are all somewhat higher than these properties in vitreous silica, probably because the silicon-carbide bonds in the network of the oxycarbide lead to a tighter, more closely packed structure. The oxycarbide glass is highly stable to temperatures up to 1600 °C and higher, because oxygen and water diffuse slowly in it.

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Bendjebbour, Mohammed, Abdellatif Cherifi i Benamar Bouhafs. "Analysis of Coupled Surface Plasmon in LHM Mediated Dielectric Gap Multilayer Structure". Photonic Sensors 10, nr 2 (21.12.2019): 113–22. http://dx.doi.org/10.1007/s13320-019-0568-3.

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AbstractThe purpose of this work is to investigate theoretically the characteristics of confined electromagnetic modes propagating along the interfaces of a multilayer device. This one dimensional (ID) sensor is formed by stacking a left-handed material (LHM) layer between a SiCt2-glass prism and a dielectric gap layer in contact with gold (Au). The results indicate that the total thickness of the LHM layer and dielectric gap, in optimum conditions, give the ability of tuning significantly the characteristics of the resonant modes correlated to surface plasmons (SPs) propagation along the interfaces of the designed device. By considering two arrangements between LHM and Au, two opposite resonant behaviors observed in p-reflectance spectra are analyzed in the angular interrogation mode and discussed thoroughly.

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Yang, L., G. J. Zhou i C. G. Lin. "Composition-dependent properties and network structure of Ge-Se-Te chalcogenide glasses". Chalcogenide Letters 20, nr 1 (styczeń 2023): 1–9. http://dx.doi.org/10.15251/cl.2023.201.1.

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Ge12.5Se87.5-xTex (0≤x≤45) glasses were selected for elucidating the composition-dependent properties and network structure of Te-containing glasses. With increasing Te content (x), Vickers hardness (Hv) and glass transition temperature (Tg) initially increased and then decreased, showing a compositional threshold at x=27.5. It is found that the compositional trend of Hv and Tg is in good accordance with the structural evolution studied by Raman spectra. The results suggest that the introduction of Te leads to the evolution of the network connectivity and average bond strength of Ge12.5Se87.5-xTex glass structure, which imposes an opposite impact on the structural properties (Hv and Tg). This work provides a new insight to the structure-property correlation of Ge-Se-Te, which would facilitate the understanding of the structural role of Te in ChGs.

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Abdel-Wahab, F., G. A. Yahya, Karam A. Ali, S. M. Salem i A. G. Mostafa. "Influence of variation (V2O5/P2O5) ratio on the local structure of iron in V2O5–BaO–Fe2O3–P2O5 glasses". Journal of Materials Research 19, nr 10 (1.10.2004): 2849–52. http://dx.doi.org/10.1557/jmr.2004.0391.

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The influence of the variation in (V2O5/ P2O5) ratio on the local structure of iron in V2O5–BaO–Fe2O3–P2O5 glass system was investigated. Infrared analysis and Mössbauer spectroscopy were used for this propose. Infrared spectroscopic analysis showed that vanadium cations act mainly as network former (NWF) while iron ions occupy both NWF and network modifier (NWM) positions. On the other hand, Mössbauer spectra indicated that, at the lowest V2O5 content, about 29% of iron ions take their positions in the glass matrix as NWF and about 71% of iron ions enter the matrix as network modifier NWM. At the highest value of V2O5 content the iron ions that enter the glass as NWF decrease to about 15%, and the iron ions which enter the glass as NWM increase to about 85%. The density and molar volume measurements also indicate the changes in the structure of these glasses.

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Lu, Xin Zhen, Yan Yan Chang, Ming Tao Xu i Bo Peng. "Microstructures of ZnO Electrospun Nanofibers on AZO Glass". Advanced Materials Research 936 (czerwiec 2014): 439–43. http://dx.doi.org/10.4028/www.scientific.net/amr.936.439.

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ZnO electrospun nanofibers were considered to be potential novel materials in applications of photovoltaic devices and sensors. AZO glass was usually used in those devices as transparent electrodes. ZnO nanofibers on AZO glass were synthesized by electrospinning and calcination process. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and photoluminescence (PL) spectrum was employed to investigate the morphology, structure and optical performance of ZnO nanofibers. Network structure composed of sheet ZnO was observed. Raman spectra and PL spectrum indicated the existence of defect states in the ZnO nanofibers.

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Mošner, Petr, Ladislav Koudelka, Josef Jirák i Miroslav Vlček. "Study of Lithium-Lead Phosphate and Borophosphate Glasses". Advanced Materials Research 39-40 (kwiecień 2008): 181–84. http://dx.doi.org/10.4028/www.scientific.net/amr.39-40.181.

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Lithium-lead phosphate and borophosphate glasses were studied in compositional series of xLi2O-(50-x)PbO-50P2O5, xLi2O-(50-x)PbO-10B2O3-40P2O5 and xLi2O-(50-x)PbO-20B2O3- 30P2O5. All glasses crystallize on heating within the range of 400-610oC. Their glass transition temperature decreases with increasing Li2O content in the region of x = 0-30 mol% Li2O and then slowly increases in all series of glasses reflecting thus changes in the bond strength of the glass structural network. Density, molar volume and chemical durability of the glasses decrease with increasing Li2O content. The 31P MAS NMR and Raman spectra show that at all glass series with the replacement of PbO by Li2O the ratio of Q2/Q1 units, present in the structure, slightly increase. The 11B MAS NMR spectra of glasses with 10 mol% B2O3 reveal the presence of only BO4 units in the glass structure, whereas the spectra of the glasses with 20 mol% B2O3 reveal also the presence of small amount of BO3 units.

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Zhao, Jun Yan, Shi Yong Luo, Xin Lin Zhang, Wen Cai Xu i Man Zhao. "A Glass Dielectric Paste for Preparation Transparent Spacers of Vacuum Glass by Screen Printing". Key Engineering Materials 519 (lipiec 2012): 252–55. http://dx.doi.org/10.4028/www.scientific.net/kem.519.252.

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Vacuum glass is a new building material with excellent energy conservation and sound insulation properties. Usually, the spacers between two pieces of flat glass substrates are mini-rings of metal. In the present research, the spacers were prepared with a glass dielectric paste by screen printing, and then sintered till them transparent. The glass dielectric paste for the preparation of transparent spacers of vacuum glass was prepared by using low melting glass powder and terpineol ethyl cellulose solution. The composition of the paste with preferable properties was evaluated as in mass percent: organic vehicle 20-25, and low melting glass powder 73-80. The rheological behaviors of the typical paste were characterized by using an ARES (RFS-III) rheometer. It is found that a weak flocculated network structure is formed in the paste for the high solid filler. The spacers were prepared by screen printing the paste on the glass substrate and then sintered. The transparent, Vickers hardness of the spacers as well as the binder forces between the spacers and the substrate is reported. The reliability of the prepared transparent spacers for the vacuum glass was discussed.

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Nesterenko, D. V., A. A. Morozov i L. L. Doskolovich. "Optical image edge detection by transmissive metal-dielectric-metal structures". Computer Optics 5, nr 45 (wrzesień 2021): 678–84. http://dx.doi.org/10.18287/2412-6179-co-853.

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The feasibility of an optical image edge detection based on metal-insulator-metal (MIM) resonance transmission structures is experimentally investigated. The structures are fabricated on a glass substrate and consist of thin aluminum layers separated by a quartz layer. The excitation of Fabry-Perot modes by an incident wave produces resonance line shapes in angular and wavelength transmission spectra. Resonance enhancement and suppression of beams using the MIM structures can be implemented for suppressing the illuminating beam and amplifying the field scattered by an object. By using the MIM structure under oblique incidence, we experimentally observe the efficient image edge detection for phase optical elements at a set of wavelengths. The obtained images of edges of the elements exhibit a directionality of image edge detection that depends on the direction of inhomogeneity gradient in the object plane, as suggested by the angular transmission spectra of the MIM structures. The results of the present work can find applications in optical information processing and optical filtering systems.

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26

Nesterenko, D. V., A. A. Morozov i L. L. Doskolovich. "Optical image edge detection by transmissive metal-dielectric-metal structures". Computer Optics 5, nr 45 (wrzesień 2021): 678–84. http://dx.doi.org/10.18287/2412-6179-co-853.

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The feasibility of an optical image edge detection based on metal-insulator-metal (MIM) resonance transmission structures is experimentally investigated. The structures are fabricated on a glass substrate and consist of thin aluminum layers separated by a quartz layer. The excitation of Fabry-Perot modes by an incident wave produces resonance line shapes in angular and wavelength transmission spectra. Resonance enhancement and suppression of beams using the MIM structures can be implemented for suppressing the illuminating beam and amplifying the field scattered by an object. By using the MIM structure under oblique incidence, we experimentally observe the efficient image edge detection for phase optical elements at a set of wavelengths. The obtained images of edges of the elements exhibit a directionality of image edge detection that depends on the direction of inhomogeneity gradient in the object plane, as suggested by the angular transmission spectra of the MIM structures. The results of the present work can find applications in optical information processing and optical filtering systems.

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Moiseyenko, V. M., V. R. Gavrilyak, M. P. Derhachov i V. S. Mukharovska. "Influence of coordination environment and dielectric contrast on the spectral-luminescent properties of europium ions in the pores of film opals". Journal of Physics and Electronics 30, nr 2 (30.12.2022): 49–54. http://dx.doi.org/10.15421/332218.

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The photoluminescence spectra of the inorganic salt of europium C6H9EuO6 × H2O in the pores of film opals, with globule diameter D ≈ 300 nm on a glass substrate, were measured. In the measured spectra the radiative transitions in the energy spectrum of Eu3+ 5D0→7F0, 5D0→7F1, and 5D0→7F2 were observed at wavelength 580 nm, 592 nm and 617 nm, respectively. The presence in the luminescence spectra of the maximum possible number of components of the Stark structure of the 5D0→7FJ (J=1–2) transitions, equal to 2J+1, and the high intensity of the 5D0 → 7F0 transition indicate that the symmetry of the luminescence centers is low, not higher than C3. The dependence of the luminescence spectra on the additional impregnation of the samples with glycerol was established: smoothing of the Stark structure and broadening of the 5D0→7F2 band were observed, as well as a decrease in the ratio of integrated intensities I(5D0→ 7F2 ) / I(5D0 →7F1) from 3.6 to 1.9.

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Dong, Chao, Hua Wang, Tingnan Yan, Jianwei Zhao, Jiwen Xu i Dawei Wang. "The Influence of CaF2 Doping on the Sintering Behavior and Microwave Dielectric Properties of CaO-B2O3-SiO2 Glass-Ceramics for LTCC Applications". Crystals 13, nr 5 (30.04.2023): 748. http://dx.doi.org/10.3390/cryst13050748.

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With the rapid development of microelectronic information technology, microelectronic packaging has higher requirements in terms of integration density, signal transmission speed, and passive component integration. Low temperature co-fired ceramics (LTCC) exhibit excellent dielectric properties and low temperature sintering properties, which meets the above-mentioned requirements. This work investigates the effects of CaF2 doping (0–16 mol%) on the glass structure, sintering behavior, crystallization, microstructure, and microwave dielectric properties of the CaO-B2O3-SiO2 (CBS) glass-ceramic system. Glass-ceramics were prepared using the conventional melting and quenching method. The physical and chemical properties of the glass-ceramics were analyzed using various techniques including TMA, SDT, FTIR, XRD, SEM, and a network analyzer. The results indicate that CaF2 doping can effectively reduce the sintering temperature and softening temperature of CBS ceramics. It also substantially improves the densification, dielectric, and mechanical properties. The appropriate amount of CaF2-doped CBS glass-ceramics can be sintered below 800 °C with a low dielectric constant and loss at high frequency (εr < 6, tanδ < 0.02 @ 10~13 GHz). Specifically, 8 mol% CaF2 doped CBS glass-ceramics sintered at 790 °C exhibit excellent microwave dielectric and thermal properties, with εr ~ 5.92 @ 11.4 GHz, tanδ ~ 1.59 × 10−3, CTE ~ 7.76 × 10−6/°C, λ ~ 2.17 W/(m·k), which are attractive for LTCC applications.

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Ogiwara, Yusuke, Kimiko Dejima, Toru Kyomen i Minoru Hanaya. "Composition Dependence of the Glass Network Structure in Li⁺-ion Conducting Glasses of (LiCl)_x(LiPO₃)_{1-_x} Studied by ³¹P MAS NMR". Key Engineering Materials 596 (grudzień 2013): 31–34. http://dx.doi.org/10.4028/www.scientific.net/kem.596.31.

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In order to obtain information about the structure of a typical Li+-ion conducting glass of (LiCl)x(LiPO3)1-x, 31P MAS NMR measurements were performed for the glass samples with different LiCl compositions x from 0 to 0.4. NMR spectra of the samples indicated the existence of two kinds of P atoms; one is that within the-P-O-P-O-P-chain of LiPO3, P(Q2), and the other is that at the ends of the chain, P(Q1). The ratio of the amount of P(Q1) to that of P(Q2) was observed to increase with the increment of x. The result shows that the addition of LiCl to the glass former of LiPO3 changes the glass network structure by cutting P-O bonds in one-dimensional phosphate chain, and the increment of the Li+-ion conductivity with the increase of x is concluded to be brought not only by the increase of the amount of LiCl dissolved into the interstices between the phosphate glass networks but also by the dispersion of the phosphate glass network structure.

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Ching-Prado, Eleicer, Amanda Watson, Héctor Miranda i Ildeman Abrego. "Optical Properties of Multilayers TiO2/SnO2:F Thin films". MRS Advances 1, nr 46 (2016): 3133–38. http://dx.doi.org/10.1557/adv.2016.281.

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AbstractThin films of TiO2/SnO2:F multilayers were prepared by spray pyrolysis technique on glass substrate. The samples were prepared using titanium (IV) isopropoxide 98%, ammonium fluoride and tin(II) chloride dehydrate extra pure as precursor materials. Thus, a TiO2 thickness dependence optical study of TiO2/SnO2:F/glass system is presented. The optical property was characterized by UV-Visible transmittance spectroscopy. For all the samples, the average transmissions in the visible wavelength region (400-800 nm) were between 69 and 84%. The optical parameters, such as the real part dielectric function ε1 and the imaginary part dielectric function ε2, of TiO2 and SnO2:F in the TiO2/SnO2:F thin films structure, determined by fitting the measured optical transmittance spectra, are presented and analyzed. Among the various classical dispersion relations for the dielectric function, the Drude model combined with the Lorentzian oscillators was used to get a good fit of transmittance in the measured spectral range. Results on related parameters such as high frequency dielectric constant, plasma frequency, film thickness and band gap are presented.

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31

Tumusange, Marie Solange, Biwas Subedi, Cong Chen, Maxwell M. Junda, Zhaoning Song, Yanfa Yan i Nikolas J. Podraza. "Impact of Humidity and Temperature on the Stability of the Optical Properties and Structure of MAPbI3, MA0.7FA0.3PbI3 and (FAPbI3)0.95(MAPbBr3)0.05 Perovskite Thin Films". Materials 14, nr 14 (20.07.2021): 4054. http://dx.doi.org/10.3390/ma14144054.

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In situ real-time spectroscopic ellipsometry (RTSE) measurements have been conducted on MAPbI3, MA0.7FA0.3PbI3, and (FAPbI3)0.95(MAPbBr3)0.05 perovskite thin films when exposed to different levels of relative humidity at given temperatures over time. Analysis of RTSE measurements track changes in the complex dielectric function spectra and structure, which indicate variations in stability influenced by the underlying material, preparation method, and perovskite composition. MAPbI3 and MA0.7FA0.3PbI3 films deposited on commercial fluorine-doped tin oxide coated glass are more stable than corresponding films deposited on soda lime glass directly. (FAPbI3)0.95(MAPbBr3)0.05 films on soda lime glass showed improved stability over the other compositions regardless of the substrate, and this is attributed to the preparation method as well as the final composition.

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32

Ganshina, Elena Alexandrovna, Vladimir Valentinovich Garshin, Ilya Mikhailovich Pripechenkov, Sergey Alexandrovich Ivkov, Alexander Victorovich Sitnikov i Evelina Pavlovna Domashevskaya. "Effect of Phase Transformations of a Metal Component on the Magneto-Optical Properties of Thin-Films Nanocomposites (CoFeZr)x (MgF2)100−x". Nanomaterials 11, nr 7 (24.06.2021): 1666. http://dx.doi.org/10.3390/nano11071666.

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The results of complex studies of structural-phase transformations and magneto-optical properties of nanocomposites (CoFeZr)x (MgF2)100−x depending on the metal alloy content in the dielectric matrix are presented. Nanocomposites were deposited by ion-beam sputtering onto glass and glass-ceramic substrate. By studying the spectral and field dependences of the transversal Kerr effect (TKE), it was found that the transition of nanocomposites from superparamagnetic to the ferromagnetic state occurs in the region of xfm~30 at%, that corresponds to the onset the formation of ferromagnetic nanocrystals CoFeZr with hexagonal syngony in amorphous dielectric matrix of MgF2. With an increase of concentrations of the metal alloy for x > xfm, the features associated with structural transitions in magnetic granules are revealed in the TKE spectra. Comparison of the spectral and concentration dependences of TKE for nanocomposites on the glass and glass-ceramics substrates showed that the strongest differences occur in the region of the phase structural transition of CoFeZr nanocrystals from a hexagonal to a body-centered cubic structure at x = 38 at.% on the glass substrates and at x = 46 at.% on glass-ceramics substrates, due to different diffusion rates and different size of metal nanocrystals on amorphous glass substrates and more rough polycrystalline glass-ceramics substrates.

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Miric, Milka, Marko Radovic, Rados Gajic, Zorana Dohcevic-Mitrovic i Zoran Popovic. "Characterisation of nanodimensional structures using spectroscopic ellipsometry". Chemical Industry 63, nr 3 (2009): 227–31. http://dx.doi.org/10.2298/hemind0903227m.

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In this paper, using spectroscopic ellipsometry we studied the optical properties of thin films, nanocrystals and carbon nanotubes in UV-VIS-NIR range. With a three-phase model, we calculated the thickness of the SiO2 film on a silicon substrate. Using the model for multilayer structure together with the Bruggeman effective medium approximation we determined the existence of roughness on a glass substrate and we calculated the thickness of that layer. We also determined the thicknesses of 12 layers, Si3N4 i SiO2 deposited alternately on a glass substrate. The dielectric function of CeO2 nanocrystal was modeled using the Tauc-Lorentz model and we calculated the value of the energy gap for this material. By analyzing the ellipsometry spectra for the carbon nanotube layer on the silicon substrate, we measured the real and imaginary part of its dielectric function.

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Chen, S. B., i Z. Y. Zhong. "Optical and Dielectric Characteristics of Photoactive Layer Thin Films for Organic Photovoltaic Cells". Applied Mechanics and Materials 217-219 (listopad 2012): 695–98. http://dx.doi.org/10.4028/www.scientific.net/amm.217-219.695.

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The thin films of poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene] (MEH- PPV) used as photoactive layer in organic photovoltaic cells were prepared on glass substrates by the spin-coating technique. The transmittance spectra of thin films were measured by a double beam spectrophotometer. The optical constants such as refractive index and extinction coefficient of the thin films were determined from the measured transmittance spectra using the method of whole optical spectrum fitting. The complex dielectric constant and the complex optical conductivity of the thin films were obtained. In addition, the optical bandgap of the thin film were calculated according to the Tauc's law. The results show that the thin films exhibit direct allowed transitions and the optical bandgap is about 2.18 eV. These results provide some useful references for the design and optimization of device structure in organic photovoltaic cells.

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35

SIMON, V., H. BAKO-SZILAGYI, M. NEUMANN, S. G. CHIUZBĂIAN i S. SIMON. "ATOMIC ENVIRONMENT IN LEAD-BISMUTHATE GLASSES CONTAINING MANGANESE". Modern Physics Letters B 17, nr 07 (20.03.2003): 291–301. http://dx.doi.org/10.1142/s0217984903005184.

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The atomic environment of 20MnO · 80(x Bi 2 O 3 · y PbO ) glass samples having the ratio of bismuth to lead atoms of 8:1 and 3:1 was investigated with respect to the thermal induced structural changes, cationic field strength and electronic structure of the compound. The position and full width at half maximum of X-ray photoelectron peaks were estimated using spectra simulation based on the summation of Lorentzian and Gaussian functions. Data obtained from XPS core-level spectra Bi 4f, Pb 4f, Mn 2p, and O 1s indicate a reduction of glass disorder both by heat treatment and by increasing the PbO content in the samples. The cations behave essentially as network formers that could be correlated with an intermediate range structure.

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Hazra, S., i A. Ghosh. "Structural properties of unconventional lead cuprate glass". Journal of Materials Research 10, nr 9 (wrzesień 1995): 2374–78. http://dx.doi.org/10.1557/jmr.1995.2374.

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Glass formation and structural properties of the unconventional lead cuprate glasses of compositions (CuO)x (PbO)100−x (mol %), are reported for the first time. X-ray diffraction and electron microscopic studies show that the glass formation occurs for x = 15-50 mol%. The compositional dependence of the density, molar volume, and glass transition temperature suggests that all glass compositions in this domain have the same topology and network connectivity. The glass structure is built up of [PbO4] tetrahedral units. On heat treatment above glass transition temperatures, the glasses crystallize to CuO and PbO. Electron Spin Resonance (ESR) spectra of the glass compositions consist of broad resonance lines.

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ZHANG, XUEHONG, ZHAO DU, HAITAO WU i YUNLONG YUE. "EFFECT OF TiO2 ON STRUCTURE AND DIELECTRIC PROPERTIES OF RO-Al2O3-B2O3-SiO2(R = Ca, Mg) GLASSES". Surface Review and Letters 20, nr 03n04 (sierpień 2013): 1350030. http://dx.doi.org/10.1142/s0218625x13500303.

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RO - Al 2 O 3- B 2 O 3- SiO 2( R = Ca , Mg ) glasses containing different concentrations of TiO 2 (ranging from 0 to 9 mol.%) were prepared by conventional melting method. When TiO 2 was present in lower concentrations (≤ 6 mol.%), Fourier-transform infrared spectroscopy (FTIR) indicated that titanium ions took part in network forming positions. However, for further increase in the concentration of TiO 2 (> 6 mol.%), FTIR data indicated the formation of TiO 4 tetrahedrons and TiO 6 octahedrons. The glass transition temperatures (Tg) were determined using a differential scanning calorimetry (DSC). The Tg variation with the concentration of TiO 2 showed an increasing trend up to 6 mol.% of TiO 2 and beyond this concentration, Tg was found to decrease. The dielectric constant εr and loss tan δ continued to decrease with the concentration of TiO 2 up to 6 mol.% and beyond that εr and tan δ were found to increase. This behavior was mainly explained in terms of the rigidity of glass network.

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Ильинский, А. В., Р. А. Кастро, М. Э. Пашкевич, И. О. Попова, А. И. Сидоров i Е. Б. Шадрин. "Импедансметрия нанокристаллитов Ag-=SUB=-2-=/SUB=-S, внедренных в нанопористые стекла". Физика твердого тела 63, nr 12 (2021): 2185. http://dx.doi.org/10.21883/ftt.2021.12.51682.176.

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The temperature dependences of the dielectric spectra of Ag2S nanocrystallites synthesized inside the channels of nanoporous glasses NPG-17 with an average diameter of filamentous pores of 17 nm are studied. The macroscopic mechanism for the occurrence of the frequency dependence of the electrical response of a nanoporous structure NPG+Ag2S is proposed. Formation of the model of mechanism is based superionic phase transition in Ag2S nanocrystallites fixed inside the channels of nanoporous glass is discussed.

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Razum, Marta, Sara Marijan, José C. Filho, Acácio A. Andrade, Anielle C. Almeida Silva, Noelio O. Dantas, Jana Pisk, Ana Šantić i Luka Pavić. "Mixed-Alkali Effect and Correlation to Glass Structure in Ionically Conductive P2O5-Al2O3-Na2O-K2O Glass System". Coatings 13, nr 1 (14.01.2023): 185. http://dx.doi.org/10.3390/coatings13010185.

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In this study, the nature of the electrical transport and structural changes resulting from the systematic substitution of Al2O3 with K2O in 40P2O5-(25−x)Al2O3-35Na2O-xK2O, where x = 5.0, 7.5, 10.0, 12.5, and 15.0 mol% (PANxK), is investigated. The impact of the changes in glass structure and its correlation to electrical properties is presented. The mixed alkali effect (MAE) is observed due to the presence of two different alkali oxides, resulting in a non-monotonic trend in the studied glass properties. The infrared spectra show the shift and diminishing of the bands related to the P–O–P/P–O–Al bridges with increasing K2O content and changes in bands related to depolymerization of the glass network, which is confirmed by the trend of the Tg values. The minimum value of DC conductivity is obtained for glass with x = 12.5 mol%. With the overall increase in alkali content, the number of non-bridging oxygens increases, also affecting the conductivity values. Frequency-dependent conductivity spectra analyzed by Summerfield, Baranovskii-Cordes and Sidebottom scaling procedures revealed interesting features and signature of the MAE in the short-range dynamics of the potassium and sodium ions, both for individual glass composition and glass series as a whole. This study showed the impact of MAE and local glass structure on the electrical features and the prevailing of one effect over the other as a function of the glass composition. MAE dominates in a wider range, but with the significant increase in alkali content, MAE is consequently overpowered.

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Abd El-Ghany, Hytham Ahmed. "Cadmium Doped Copper Containing Phosphate Glass as a Bandpass Filter for Solar Cell Protection". JOURNAL OF ADVANCES IN PHYSICS 14, nr 2 (1.07.2018): 5488–503. http://dx.doi.org/10.24297/jap.v14i2.7450.

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A glass system of composition 44P2O5-38ZnO-2CuO-(16-x)Na2O-xCdO (where, x = 1, 2, 3, 4, and 5 mol%) has been prepared using the conventional melt quenching technique. XRD patterns confirmed the amorphous nature for the prepared samples. Archimedesâ€™ method was used to determine the density of the prepared glass samples then the molar volume was calculated. The optical spectroscopic investigations of the prepared glass samples were carried out over the spectral range (190-1100 nm). The transmission spectra revealed that the prepared glass samples behave as bandpass filters in the visible region. The absorption studies were employed to determine the optical band gap and Urbach energy. The spectral distribution of the refractive index assured the lowest dispersion of the glass in the visible region. Other physical parameters such as the extinction coefficient, the optical conductivity, and the complex dielectric constant were evaluated. The results suggested the practicality of employing such low-cost glass as a bandpass filter for optical applications such as UV-elimination and solar cell protection. The role of CdO as a network modifier in the phosphate glass was revealed.

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Yu, Xueyi, Zeming Fang, Qianfa Liu, Dan Li, Yundong Meng, Cheng Luo, Ke Wang i Zhiyong Lin. "Effects of Peroxide Initiator on the Structure and Properties of Ultralow Loss Thermosetting Polyphenylene Oxide-Based Composite". Polymers 14, nr 9 (26.04.2022): 1752. http://dx.doi.org/10.3390/polym14091752.

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Although thermosetting polyphenylene oxide- (PPO) based composites with excellent dielectric properties have been widely accepted as superior resin matrices of high-performance copper clad laminate (CCL) for 5G network devices, there has been limited information regarding the composition–process–structure–property relationships of the systems. In this work, the effects of peroxide initiator concentration on the structure and dielectric properties of a free radical cured ultralow loss PPO/Triallyl isocyanate (TAIC) composite system were studied. As expected, the glass transition temperature (Tg) and storage modulus increased with the advancing of crosslinking, whereas the dielectric loss showed an “abnormal” rise with the increase in crosslink density. Extensive studies were carried out by varying the initiator contents and characterizing the structure with spectroscopy, thermal analysis, and positron annihilation lifetime spectrum (PALS) techniques. The results show that the competition of polarity, crosslink density, free volume, and free TAIC are the key factors determining the dielectric properties of the composites.

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Ilinskiy A.V., Castro R.A., Pashkevich M.E., Popova I.O., Sidorov A.I. i Shadrin E.B. "Impedancemetry of Ag-=SUB=-2-=/SUB=-S nanocrystallites embedded in nanoporous glasses". Physics of the Solid State 64, nr 14 (2022): 2437. http://dx.doi.org/10.21883/pss.2022.14.54347.176.

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The temperature dependences of the dielectric spectra of Ag2S nanocrystallites synthesized inside the channels of nanoporous glasses NPG-17 with an average diameter of filamentous pores of 17 nm are studied. The macroscopic mechanism for the occurrence of the frequency dependence of the electrical response of a nanoporous structure NPG-17 + Ag2S is proposed. Formation of the model of mechanism is based superionic phase transition in Ag2S nanocrystallites fixed inside the channels of nanoporous glass is discussed. Keywords: silver sulfide, Ag2S, nanoporous glasses, nanostructured materials, impedancemetry.

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Savvova, Oksana, Gennady Voronov, Svіatoslav Rіabinin, Alexey Fesenko i Dmitry Svishov. "FEATURES OF THE STRUCTURE FORMATION OF SPODUMENS-CONTAINING GLASS-CRYSTAL MATERIALS AFTER HEAT TREATMENT". Bulletin of the National Technical University "KhPI". Series: Chemistry, Chemical Technology and Ecology, nr 1(5) (15.05.2021): 38–43. http://dx.doi.org/10.20998/2079-0821.2021.01.06.

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The promising areas of application of spodumene–containing glass–crystalline materials in various branches of science and technology, in particular, to increase the defense capability of the state, have been determined. The relevance of the development of lightweight high–strength sitalls based on them, taking into account the aspects of energy saving for obtaining armored elements, has been determined. It has been established that the use of IR spectroscopy is promising for studying the nanostructure of glass–crystalline materials. The compositions of lithium aluminum silicate glasses and the modes of their heat treatment have been developed. The features of the structure formation of spodumene–containing glass–crystalline materials obtained under the conditions of two–stage low–temperature heat treatment have been investigated. Taking into account the analysis of the nature of the IR spectra of chain silicates, the structure of glass–crystalline materials was investigated according to the IR spectra and the nature of structure formation was established depending on the initial composition of the glass. It has been established that the formation of a structural glass network with the participation of tetrahedra [AlO4], [BO4] and [SiO4] and the presence of cybotaxic groups [Si2O6] allows, under conditions of two–stage low–temperature treatment, to provide bulk crystallization of spodumene–containing glass–crystalline materials. It has been established that the formation of the vitrified structure of glass–crystalline materials allows to ensure their high values of Vickers hardness, microhardness and crack resistance and by the presence of a glass phase, which plays the role of a damper, to ensure their high armor resistance. This will increase the efficiency and make it possible to use them as an energy–destructive and energy–absorbing layer in the composition of the armor element «metal alloy – ceramics – sitall». The introduction of spodumene–containing glass–crystalline materials will increase the competitiveness of competitive domestic armored elements for personal protection.

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Yew, Eeu Tien, Wan Ming Hua, Poh Sum Wong, Nur Amanina Mat Jan, Zuhairi Ibrahim i Rosli Hussin. "Structural Study of Antimony Borate Glass System Doped with Transition Metal Ions Using Infrared and Raman Spectroscopy". Advanced Materials Research 501 (kwiecień 2012): 51–55. http://dx.doi.org/10.4028/www.scientific.net/amr.501.51.

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A series of Antimony Borate glass samples were investigated to determine the structural feature. The glass samples from the series of xSb2O3:(1-x)B2O3 with composition of 20≤x≤60 mol% and 0.6 Sb2O3:0.4B2O3:y with y is 0.01 mol% of Nb2O5, CuO, ZnO system have been prepared using melt-quenching technique. The structural properties of Sb2O3 host and the introduction of dopents onto the host sample has been investigated using Infrared and RAMAN Spectroscopy. The result of IR and Raman Spectroscopy revealed that the network structure of the studied glasses is mainly based on BO3 and BO4 units placed in different structural groups, the BO3 units being dominant. IR spectra obtained shows conversion of BO3 to BO4 units upon the introduction of Sb2O3 commonly known as boron anomaly effect. The glass network can be modified with the presence of Sb2O3 and activator ions. The significant behavior in Raman Spectra indicates the presence of boroxol groups consisting of pure BO3 groups and mixed BO3-BO4 structural units. This study shows that the vibrational spectroscopy (Infrared and Raman) provide useful method, and inter-complementary information about the structural properties of antimony modified borate glasses.

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Ciang, H. Y., S. M. Hsu, S. W. Yung, Y. J. Chen, C. H. Lin, C. H. Hsu, J. S. Lin i J. Lin. "Properties and Structure Investigation of Rare Earth-Doped Zinc Aluminum Silica-Phosphate Glasses". Advanced Materials Research 509 (kwiecień 2012): 150–51. http://dx.doi.org/10.4028/www.scientific.net/amr.509.150.

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This study explores a series of optical, thermal, and structural properties based on zinc-aluminum phosphate glasses that doped with varied rare earth (RE) elements Yb2O3 and P2O5 components replaced by SiO2. It was found that for 60P glasses system, 7 mol% Yb2O3 doped has the maximum fluorescence but quenching when Yb2O3 is doped up to 9 mol%. In addition, with increasing the content of Yb2O3 the absorption intensity increased. According to Raman spectra, we found the Yb3+ and Si4+ ions for the impact of network structure of glass, SiO2 added to make the network structure of phosphate glasses at 450-500cm-1 and 600-650cm-1 were formed O-T-O bond and T-O-T bond(T=Si, Al).

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Abdulsamee Fawzi Abdul Aziz Albayati. ""Preparation of SnO2 thin films by doping with F-1 ions using chemical spray pyrolysis"". Tikrit Journal of Pure Science 20, nr 4 (10.02.2023): 107–13. http://dx.doi.org/10.25130/tjps.v20i4.1221.

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In this paper, the structural and optical properties of pure Tin Oxide and doped by Fluorine (F). Thin films were studied prepared by chemical spray pyrolysis on glass substrates at temperature 400oC. The nature of crystallization of the compounds was examined by using X-Ray diffraction technique which showed that the prepared thin films are polycrystalline structure, and the doping processes didn,t show any obvious differences on the crystalline structure of (SnO2). The DC conductivity measurements of the samples were performed by means of a two probe method. The activation energies were computed from the plots of σdc versus 1000/T. To obtain the optical parameters, the absorption and transmittance spectra were recorded in the wave length range 300-1100 nm, the energy gap of the direct and indirect allowed transition were calculated. The optical parameters such as absorption coefficient (α), refractive index (n), extinction coefficient (Ko), dielectric constant (ε'), and dielectric loss (tanδ), were also investigated.

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OTHMAN, H. A., M. M. ALQAHTANI, M. REBEN i EL S. YOUSEF. "RAMAN GAIN AND STRUCTURAL OF TELLURITE-PHOSPHATE GLASSES WITH DIFFERENT MODIFIERS DOPING WITH Er2O3". Chalcogenide Letters 17, nr 4 (kwiecień 2020): 207–15. http://dx.doi.org/10.15251/cl.2020.174.207.

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A glass series of Te-glasses (70TeO2- 10P2O5- 10ZnO- 5PbF2) modified with 5mol % of different modifiers (WO3, Al2O3, CdO, SrO, BaO), that was then doped with 600ppm Er2O3 was prepared by melt quench technique. The effect of modifier oxide on the Teglass structure was studied using Raman spectroscopy. The Obtained Raman spectra reveal the characteristic structural units TeO4 and TeO3. Er2O3 doping along with the type of oxide modifier influenced the tellurite glass network and hence the Raman spectral features. The change in the Boson peak features depend on the rare earth ion doping. The obtained Raman spectra were deconvoluted to follow the structural changes. The deconvoluted data show a transformation of TeO4 to TeO3 upon the addition of metal oxides. Due to the higher coordination of WO3 and Al2O3 that offers more oxygens when compared with alkaline modifiers, the TeO3 structural group is dominated. Raman gain was calculated for the prepared glasses. Al2O3 modified glass sample has the highest Raman gain.

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Wang, C. Y., Z. X. Shen i J. Z. Zheng. "High-Temperature Properties of a Low Dielectric Constant Organic Spin-on Glass for Multilevel Interconnects". Applied Spectroscopy 55, nr 10 (październik 2001): 1347–51. http://dx.doi.org/10.1366/0003702011953469.

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In this paper, we report on the thermal properties of a low-dielectric-constant organic spin-on glass, methyl silsesquioxane (MSQ), an important material for semiconductor device fabrication. The compositional and structural changes of this MSQ material, when heated in air and N 2, were investigated in detail with Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric analysis (TGA). MSQ transforms to thermal oxide SiO 2 above 500 °C when heated in air, and it forms oxygen-deficient SiO 2 above 700 °C in N 2. Our results suggest that a cure temperature higher than the current 425 °C is preferred to form films with better cross-linked network structure.

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Li, Haijian, Hao Zou, Zhihua Sun, Yi Xu, Changjian Wang, Xiao Xie, Jianhua Yi i Fengqi Zhao. "Spectroscopic and Surface Crystallization Characterizations of Yttrium-Doped Phosphate Glasses". Crystals 12, nr 1 (14.01.2022): 109. http://dx.doi.org/10.3390/cryst12010109.

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The composition, structure, and thermal behaviors of yttrium-containing phosphate glasses were studied in this work, and the glass-ceramics were prepared via the two-step crystallization method. The XRD and SEM-EDS results show the forming range of the phosphate glass system and the formation of YPO4 (xenotime) due to the addition of excessive Y2O3. The spectroscopic characterization of these glasses presented shifts of the infrared and Raman bands, demonstrating the depolymerization of the glass network and the formation of novel P–O–Y bonds, and the deconvoluted Raman spectra also exhibited the occurrence of the disproportionation reaction in the glass melting process. The content of non-bridging oxygen (NBOs) from the UV–vis spectra first increased and then decreased with increasing Y2O3. The thermal behaviors show that the Y2O3 reduced the crystallization peak temperature and the thermal stability of the glasses. The crystalline behaviors of the phosphate glass matrix were investigated at different crystallization times of 2–10 h, and a transformation of the crystallization mechanism from surface to volume crystallization was found. The yttrium phosphate glass-ceramics crystallized for 10 h exhibited transformation of the main crystalline phases with increasing Y2O3, and the grain-oriented crystalline surface became irregular.

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ARDELEAN, I., N. MUREŞAN i P. PĂŞCUŢĂ. "IR AND RAMAN SPECTROSCOPIC INVESTIGATIONS OF Cr2O3-TeO2-B2O3-SrO GLASSES". Modern Physics Letters B 18, nr 09 (10.04.2004): 367–73. http://dx.doi.org/10.1142/s0217984904006974.

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The Cr 2 O 3 content influence on the structure of 70 TeO 2·25 B 2 O 3·5 SrO glasses, was investigated by infrared and Raman spectroscopies. The results show that BO 3 and BO 4 are among the main structural units in the investigated glasses, together with TeO 3 and TeO 4 units. The presence of chromium ions located in the glass network is well evidenced in the IR and Raman spectra.

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