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Incarceration of iodine in a pyrene-based metal-organic framework
摘要： A pyrene-based metal–organic framework (MOF) SION-8 captures iodine (I2) vapour with a capacity of 460 mg g–1 MOF and 250 mg g–1 MOF at room temperature and at 75 °C, respectively. Single-crystal X-ray diffraction analysis and van der Waals-corrected density functional theory calculations confirm the presence of I2 molecules within the pores of SION-8 and their interaction with the pyrene-based ligands. The I2-pyrene interactions in the I2-loaded SION-8 lead to a 104-fold increase of its electrical conductivity compared to the bare SION-8. Upon adsorption, ≥95% of I2 molecules are incarcerated and cannot be washed out, signifying the potential of SION-8 towards the permanent capture of radioactive I2 at room temperature.
关键词： charge transfer,conductivity,impedance spectroscopy,iodine capture,metal–organic framework
更新于2025-09-10 09:29:36
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tilt Grain Boundary on Oxygen-ion movement In Yttria-Stabilized Zirconia: Insights from molecular dynamics
摘要： We present a new methodology for investigating the combined effect of the Σ5(310)/[001] symmetric tilt grain boundary (GB) and the local cation environment in polycrystalline yttria stabilized zirconia (YSZ) on two important quantities that determine the ionic conductivity, namely, (i) the local hopping rate of O2- ion and (ii) the probability of O2--ion -vacancy pairs within the YSZ structure. How these quantities vary with distance to the GB core are estimated for the first time using waiting time distributions associated with O2- ion hop events in molecular dynamics simulations. We conclude that indeed fewer hop events occur in the presence of a GB. However, the GB effect can be felt at a far greater distance than previously believed. Most importantly, interactions between the O2- ions, nearby cations and the GB results in a hopping behavior that is different from one observed in single-crystal YSZ. Anisotropy in O2- ion movement in the vicinity of the GB is also studied. These results and the use of our novel technique have a direct implication on the development of improved models for ionic conduction in solid state electrolytes.
关键词： Ionic conductivity,molecular dynamics,yttria stabilized zirconia,grain boundary
更新于2025-09-10 09:29:36
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Transport Properties of CuInTe2 Thin Films Obtained by the Electrochemical Route
摘要： CuInTe2 (CIT) thin ?lms were potentiostatically electrodeposited onto cadmium sul?de thin ?lms coated on ?uorine doped tin oxide (FTO) glass in an aqueous bath at 75°C by the standard three-electrode system at ?0.7 V and ?0.8 V, with respect to an Ag/AgCl reference electrode. The electrodeposited layers were heat treated at ～80°C in air ambient for 60 min. X-ray diffraction pattern and Raman analysis con?rmed the formation of chalcopyrite CIT thin ?lms upon heat treatment. The optical band gap of heat treated CIT ?lms was found to be ～1.0 eV and 0.95 eV deposited at ?0.7 V and ?0.8 V, respectively. Compact and good adhesive growth of CIT layers onto CdS coated FTO substrates is con?rmed by ?eld emission scanning electron microscopy. The current density–voltage (J–V) and capacitance–voltage (C–V) measurement was studied to understand the electronic quality of material for development of CIT layers for solar cell applications. The current density was found to be increased by two orders of magnitude upon low-temperature heat treatment. The capacitance–voltage measurement showed sharp depletion and accumulation region. The built in potential was found to be ～60 mV and 145 mV in the as-deposited samples, deposited at ?0.7 V and ?0.8 V, respectively, whereas upon heat treatment it shifted to 159 mV and 210 mV. The capacitance of the CIT ?lms was found to be a function of applied bias and increased with increasing the bias voltage. The depletion width of the heat treated sample was found to be ～20 nm and 200 nm for the sample deposited at ?0.7 V and ?0.8 V, respectively. Thus, the sample deposited at ?0.8 V shows optimum electronic properties and is found to be suitable for optoelectronic applications.
关键词： C–V measurement,Hall measurement,conductivity,Electrodeposition,CuInTe2
更新于2025-09-10 09:29:36
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Optical transparency and electrical conductivity of intermediate filaments in Müller cells and single-wall carbon nanotubes
摘要： Presently we investigated the electrical conductivity and optical transparency of Müller cell intermediate filaments. For comparison, the same properties were also explored in the model system of single-wall carbon nanotubes. We report the method of separation and purification of porcine (Sus scrofa domestica) intermediate filaments, extracted from the retinal Müller cells. We also report experimental and theoretical methods of measurements and calculations of the resistivity and light transmission yield by the intermediate filaments and single wall carbon nanotubes. The measured resistivity values were (4.7 ± 0.3) × 10?4 Ω?m?1?cm2 and (2.8 ± 0.2) × 10?4 Ω?m?1?cm2 at 5 °C (278 K), for the intermediate filaments and single wall carbon nanotubes, respectively, being quite close to those of typical metals. We report a method for measuring the light energy transmission by these nanostructures. We found that they efficiently transfer excitation energy along their axis, with the light reemitted at their other end. The measured yields of transferred light energy were 0.50 ± 0.03 and 0.26 ± 0.02 for intermediate filaments and single wall carbon nanotubes, respectively (λexc = 546.1 nm; T = 288 K). The reported results are novel, providing a direct confirmation of the earlier proposed quantum mechanism of light energy transport in the inverted retina of vertebrates. Our data also show that Müller cell intermediate filaments, in addition to their cytoskeletal function, are capable of providing for the light energy transfer within the inverted retina. The data obtained enable a significant progress in our understanding of the high-contrast vision of the vertebrate eyes. The most important conclusion of the current study is the discovery of light energy propagation along natural biological nanofibers (intermediate filaments). This result is completely novel and unique, being reported for the first time.
关键词： Müller cell,Intermediate filament,Porcine retina,Light transmission,Electric conductivity
更新于2025-09-10 09:29:36
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Study of dielectric relaxation and thermally activated a.c. conduction in multicomponent Ge10-xSe60Te30Inx (0 ≤ x ≤ 6) chalcogenide glasses using CBH model
摘要： Amorphous Ge10-xSe60Te30Inx (0 ≤ x ≤ 6) chalcogenide glasses were prepared by melt quench technique. Surface morphology with the chemical composition of the prepared glass was examined using SEM and EDS analysis respectively. Dielectric properties and a.c. conductivity of the multicomponent Ge10-xSe60Te30Inx (0 ≤ x ≤ 6) chalcogenide glasses have been examined in the frequency range 100Hz to 1MHz and temperature range 303 to 328K. It was noticed that dielectric constant and dielectric loss decreases with the increase of frequency and increases with the increase of temperatures. Frequency and temperature dependence of dielectric constant was explained by orientational polarization. The variation of dielectric loss with frequency and temperature was explained by conduction loss and theory of single polaron hopping of charge carriers suggested by Elliot and Shimakawa for chalcogenide glasses. The experimental results show that a.c. conductivity follows the power law where s<1 and value of s decreases with the increase of temperature. The present findings of a.c. conductivity and variation of s with temperatures are reasonably well interpreted in terms of CBH model.
关键词： a c conductivity,dielectric relaxation,Chalcogenide glasses,CBH model,activation energy.
更新于2025-09-10 09:29:36
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Effect of Heat Treatment on The Crystal Structur, Electrical Conductivity and Surface of Ba <sub/>1.5</sub> Sr <sub/>0.5</sub> Fe <sub/>2</sub> O <sub/>5</sub> Composite
摘要： The Composite of Ba1,5Sr0,5Fe2O5 has been synthesized by using powder metallurgy technique. The Ba1.5Sr0.5Fe2O5 were prepared from BaCO3, SrCO3 and Fe2O3 raw materials with a specific weight ratio. The three materials were synthesized by powder metallurgy under heat treatment at 800 °C, 900 °C, and 1000 °C for 5 hours. All the three samples were characterized by using X-ray Diffraction (XRD) to determine the crystal structure and crystal size, LCR meter to determine the conductivity, and Scanning Electron Microscope (SEM) to observe the morphological of the composites. The phase analysis result showed that the composite consists of several minor phases such as BaO2, SrO2, and Fe2O3. The Crystal size of composite Ba1.5Sr0.5Fe2O5 decreased while increases the strain of crystal with increasing of sintering temperature. The crystal size of the Ba1.5Sr0.5Fe2O5 composite is 3.55 nm to 7.23 nm and value of strain is 8.47% until 3.90%. Based on the conductivity measurement, it was obtained that the conductivity of the Ba1.5Sr0.5Fe2O5 composite decreased with increasing sintering temperature. It was also noticed that the conductivity increased with increasing of frequency. The conductivity ranged from 6.619?10-7 S/cm to 65.659?10-7 S/cm. The energy dispersive spectroscopy (EDS) analysis showed that several dominant elements were a good agreement with the phase analysis.
关键词： surface,Ba1.5Sr0.5Fe2O5,conductivity,Composite,X-ray diffraction
更新于2025-09-10 09:29:36
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Hydrogen-bonded and supramolecular ferroelectricity in a new hybrid (C<sub>12</sub>H<sub>25</sub>NH<sub>3</sub>)<sub>2</sub>CoCl<sub>4</sub>
摘要： A new organic-inorganic layered halide perovskite ((C12H25NH3)2CoCl4) has been synthesized and characterized by: chemical analysis, X-ray powder diffraction, differential scanning calorimetry, and differential thermal analysis thermographs. The dielectric and ferroelectric properties have been investigated. Analysis of the ac conductivity σac (ω, T) measured in the temperature interval from 110K to 370K and at selected frequencies in the range 1 kHz< f<100 kHz and the results show that the Jonscher universal power law is accurately obeyed. The existence of ferroelectricity has been demonstrated by the hysteresis P-E loop. The collective data evidenced that the hybrid behaves as a proper ferroelectric rather than a relaxor one and undergoes an order-disorder ferroelectric phase transition at the Curie temperature Tc (Tc?360K) accompanied with a structural distortion from an intercalated to non- intercalated state as the other Co and/or Zn hybrids. Since the room temperature space group of the hybrid is centrosymmetric (P21/c), the ferroelectricity should be due to the supramolecular interaction which results from the induced dipoles. The hydrogen bonding system of the type N-H....Cl plays the key role in the mechanism of supramolecular ferroelectricity.
关键词： ac induced conductivity and complex dielectric permittivity,phase transition,Supramolecular ferroelectricity,polarization
更新于2025-09-10 09:29:36
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A Room-Temperature High-Conductivity Metal Printing Paradigm with Visible-Light Projection Lithography
摘要： Fabricating electronic devices require integrating metallic conductors and polymeric insulators in complex structures. Current metal-patterning methods such as evaporation and laser sintering require vacuum, multistep processes, and high temperature during sintering or postannealing to achieve desirable electrical conductivity, which damages low-temperature polymer substrates. Here reports a facile ecofriendly room-temperature metal printing paradigm using visible-light projection lithography. With a particle-free reactive silver ink, photoinduced redox reaction occurs to form metallic silver within designed illuminated regions through a digital mask on substrate with insignificant temperature change (<4 °C). The patterns exhibit remarkably high conductivity achievable at room temperature (2.4 × 107 S m?1, ≈40% of bulk silver conductivity) after simple room-temperature chemical annealing for 1–2 s. The finest silver trace produced reaches 15 μm. Neither extra thermal energy input nor physical mask is required for the entire fabrication process. Metal patterns were printed on various substrates, including polyethylene terephthalate, polydimethylsiloxane, polyimide, Scotch tape, print paper, Si wafer, glass coverslip, and polystyrene. By changing inks, this paradigm can be extended to print various metals and metal–polymer hybrid structures. This method greatly simplifies the metal-patterning process and expands printability and substrate materials, showing huge potential in fabricating microelectronics with one system.
关键词： hybrid material printing,metal patterning,high conductivity,flexible electronics,room-temperature printing
更新于2025-09-10 09:29:36
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Simulation and Experimental Study on Properties of Ag/SnO <sub/>2</sub> Contact Materials Doped with Different Ratios of Ce
摘要： SnO2 in the Ag/SnO2 contact material is a kind of high hardness and almost insulated wide bandgap semiconductor material. In the process of use, the contact resistance is larger and the temperature rise is higher, which reduces the reliability of contacts and shortens the electrical life. In order to improve the properties of Ag/SnO2 contact materials, based on the first principle of density functional theory, this paper presents a method of doping SnO2 with the calculation of different proportions of rare earth Ce electrical and mechanical properties. The results of energy band, density of state, and elastic constant show that when the doping ratio of Ce is 0.125, the electron mobility is the highest, the conductivity is the best; the hardness decreases, and the universal elastic anisotropy index is the smallest. Finally, in the experiment, SnO2 powders with different doping ratios are prepared by the sol-gel method, and Ag/SnO2 contacts with different doping proportions are prepared by powder metallurgy. Arc energy, contact resistance, and hardness are measured; scanning electron microscopy was used to observe and analyze the surface morphology. The final simulation and experimental results are well matched.
关键词： doping,contact materials,rare earth Ce,conductivity,hardness,Ag/SnO2
更新于2025-09-10 09:29:36
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Structural and dielectric properties of BaTi0.5 (Co0.33 Mo0.17) O3 perovskite ceramic
摘要： The polycrystalline sample BaTi0.5 (Co0.33 Mo0.17) O3 was synthesized by the sol-gel method. The effect of replacing titanium by cobalt and molybdenum on the structural and electrical properties of our compound was investigated. The results of X-ray diffraction (XRD) at room temperature showed a pure tetragonal perovskite. The electrical response was studied by complex impedance spectroscopy over a broad frequency range (30 - 106 Hz) at different temperatures. The values of ac conductivity were fitted by Jonscher’s law σ(ω) = σDC + Aωn and supported by the correlated barrier hopping (CBH) mechanism. Complex impedance analysis confirmed the existence of an electrical relaxation in the compound. The dielectric constant and the dielectric loss decreased with the increase in frequency. This behavior can be explained by the presence of the Maxwell–Wagner type of polarization responsible for the electric conduction. The modulus plots were characterized by the Havriliak–Negami (H-N) and the empirical Kohlrausch–Williams–Watts (K.W.W.) functions. The Normalized plot of the imaginary part of modulus indicates that the dynamical processes are temperature independent.
关键词： Impedance spectroscopy,Sol-gel processes,Permittivity,X-ray diffraction,Conductivity
更新于2025-09-10 09:29:36