Open Access
43
In this paper, we propose a facile and efficient strategy for synthesizing mesoporous BaSnO3 with a surface area as large as 67 m(2)/g using a peroxo-precursor decomposition procedure. As far as we know, this is the largest surface area reported in literature for BaSnO3 materials and may have a potential to greatly promote the technological applications of this kind of functional material in the area of chemical sensors, NOx storage, and dye-sensitized solar cells. The structure evolution of the mesoporous BaSnO3 from the precursor was followed using a series of techniques. Infrared analysis indicates large amount of protons and peroxo ligands are contained in the peroxo-precursor. Although the crystal structure of the precursor appears cubic according to the analysis of X-ray diffraction data, Raman and Mössbauer spectroscopy results show that the Sn atom is offset from the center of [SnO6] octahedron. After calcination at different temperatures, the precursor gradually transforms into BaSnO3 by release of water and oxygen, and the distortion degree of [SnO6] octahedral decreases. However, a number of oxygen vacancies are generated in the calcined samples, which are further confirmed by the physical property measurement system, and they would lower the local symmetry to some content. The concentration of the oxygen vacancies reduces simultaneously as the calcination temperature increases, and their contributions to the total heat capacity of the sample are calculated based on theoretical analysis of heat capacity data in the temperature region below 10 K.
4Heat capacity of cytisine – the drug for smoking cessation
Heat capacity of cytisine – the drug for smoking cessation
63Effect of Dy-substitution on the structural, vibrational, and multiferroic properties of BiFeO3 nanoparticles
Dysprosium (Dy) modified BiFeO3 [Bi1−xDyxFeO3 (x = 0.05, 0.10, and 0.15)] nanoparticles have been synthesized by a low temperature co-precipitation method. Rietveld analysis of X-ray diffraction data reveals a transformation from rhombohedral structure to orthorhombic structure with increase in the Dy concentration. From the transmission electron microscopy analysis, it is observed that the particle sizes of Bi1−xDyxFeO3 (x = 0.05, 0.10, and 0.15) nanoparticles range between 50–70, 40–50, and 30–50 nm, respectively. Raman spectra of Bi1−xDyxFeO3 (x = 0.05) belonging to rhombohedral (R3c) structure show 4A1 and 7E fundamental Raman modes in the range of 100–650 cm−1 and two-phonon scattering modes such as 2A4 (longitudinal optical), 2E8 (transverse optical (TO)), and 2E9 (TO) in the range of 950–1270 cm−1. Suppression, broadening, and shifting of Raman modes have been observed with further increase in Dy concentration. The fundamental Raman modes of Bi1−xDyxFeO3 (x = 0.15) are assigned under orthorhombic (pnma) rather than rhombohedral (R3c) as the Rietveld analysis of X-ray diffraction data predicts a structural transformation for this particular composition. A complete suppression of two phonon modes has been noticed for this composition. An anomaly in the temperature dependent dielectric studies has been observed in all the samples at the vicinity of Neel temperature indicating a magnetic ordering, and an increase in magnetization with increase of Dy concentration in BiFeO3 is noticed from the room temperature magnetic studies. P–E hysteresis loop studies show a decrease of remnant polarization (Pr) with the increase in Dy concentration and disappearance of hysteresis loop occurs for Bi1−xDyxFeO3 (x = 0.15) depicting a transformation from non-centrosymmetric (R3c) to centrosymmetric (Pnma) system.
Read moreRole of the dispersion correction in analysis of X-ray diffraction data
The role of the dispersion correction in the analysis of X-ray diffraction data of lithium fluoride has been considered by applying the recent theoretical and experimental values of the dispersion corrections.
Read more61Standard methods for heat capacity measurements on a Quantum Design Physical Property Measurement System
Standard methods for heat capacity measurements on a Quantum Design Physical Property Measurement System
1Electrospinning TiO<inf>2</inf> nanofibers, nanoparticle/nanofibers as a photoanode for high performance dye sensitized solar cell
Dye sensitized solar cell(DSSC) possessed both low cost and high energy conversion efficiency has attracted considerabale research interests, enabling a promising next generation solar cell. DSSC based on TiO 2 photoanode is a low-cost, high efficient photovoltaic device for solar energy conversion. Conventional commercial photoanode consist essentially of anatase crystalline titanium dioxide which played a key role in dye adsorption and electron transport. However, nanoparticles were not conducive to the separation and transmission of electrons and holes. One-dimensional (1D) nanostructure photoanode was replaced the nanoparticle film, which provided a direct pathway improve the efficiency. TiO2 nanofibers(NF) synthesized via electrospinning, has evealed distinct properties as a photoanode in DSSC. An innovation of TiO 2 nanoparticle (NP)/TiO2 nanofibers double layers was fabricated to form composite photoanode in our work. These TiO2 NP/NF composite photoanodes have exhibited high performance applied in DSSC. The TiO2 NF was described in terms of crystallinity, morphology and chemistry through BET, XRD, TEM, EDX, FESEM, XPS, FT-IR, TG. After via sintering treatment, NF did not change significantly and was used as photoanode scattering layers in DSSC. Based on these TiO 2 NP/NF double layer as composite photoanode, the devices were sensitized with N719 and using a I 2 /I3− electrolyte solution with acetontrile and ethylene carbonate as co-solvent, exhibiting a best efficiency of 6.5%. Meanwhile, the devices based on NP photoanode with the same electrolyte showed an efficiency of 3.44%. Addtionally, the effect of NF films with different thickness on the devices performence was investigated in detail, The optimized thickness of TiO2 NF photoanode was electrospinning for 15min. The improved efficiency was attributed to the increased dye adsorption on TiO2 NF and the improved short-circuit density. The high photovoltaic response of DSSC based on NP/NF double layer were attributed to the surface area(BET: 49.87 m2/g) and volume of NF (0.179 mL/g) of the NF, and the low electron recombination rate. Electrospinning technology provides a new approach for the preparation of large area, the stability and photovoltaic performance of the devices dye-sensitized solar cells and their future commercial applications.
Read more33Low temperature heat capacity Study of Fe(PO3)3 and Fe2P2O7
Low temperature heat capacity Study of Fe(PO3)3 and Fe2P2O7
6Low temperature heat capacity and thermodynamic function of BaZrO3 and PbZrO3
Low temperature heat capacity and thermodynamic function of BaZrO3 and PbZrO3
47Structural studies of hydrated germanium X-type zeolite via Rietveld analysis of synchrotron powder X-ray diffraction data
Structural studies of hydrated germanium X-type zeolite via Rietveld analysis of synchrotron powder X-ray diffraction data
Read more92Controlling the microstructure and properties of titania nanopowders for high efficiency dye sensitized solar cells
Controlling the microstructure and properties of titania nanopowders for high efficiency dye sensitized solar cells
Methodology to Characterize Thermal Properties of Thin Film Superconductors Using a DynaCool Physical Property Measurement System
We describe a methodology to characterize heat capacity <bold xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C<inline-formula><tex-math notation="LaTeX">$_{p}$</tex-math></inline-formula></b> of 1 μm thick Nb thin films at a temperature range of 60 K to 1.8 K. We used a commercially available relaxation calorimeter device by Quantum Design DynaCool Physical Property Measurement System (PPMS). The mass of thin films is negligible compared to the minimum coarse estimate required by the heat capacity module of the PPMS. To overcome this limitation, a vertical stack of multiple diced substrates of the same material with uniform dimensions of 2.5 mm x 2.5 mm was joined by cryogenically compatible grease to form a stack resulting in a larger effective mass of the target film. The critical behavior of heat capacity in the region of the transition temperature is demonstrated. The heat capacity of Nb thin films was measured by subtracting the total heat capacity of the joining grease and stack of substrate used as addenda. Results in this work prove that a vertical stacking approach is viable for measuring the behavior of deposited thin films.
Read more4Low temperature heat capacities and thermodynamic functions of two novel cobalt (II) and nickel (II) mononuclear compounds constructed with o-pthalate and phenanthroline
Low temperature heat capacities and thermodynamic functions of two novel cobalt (II) and nickel (II) mononuclear compounds constructed with o-pthalate and phenanthroline
Read more118Precision and accuracy of the heat-pulse calorimetric technique: lowtemperature heat capacities of milligram-sized synthetic mineral samples
Precision and accuracy of the heat-pulse calorimetric technique: lowtemperature heat capacities of milligram-sized synthetic mineral samples
Read more34Thermodynamic insights into n-alkanes phase change materials for thermal energy storage
Thermodynamic insights into n-alkanes phase change materials for thermal energy storage
6Low temperature heat capacity, standard entropy, standard enthalpy and magnetic property: a new 1D CuII coordination polymer incorporating tetrazole-1-acetic acid and p-nitrobenzoic acid.
A new 1D CuII coordination polymer, formulated as {[Cu(TZA)(PNA)]·H2O}n (1) (HTZA = tetrazole-1-acetic acid, HPNA = p-nitrobenzoic acid), was synthesized and structurally characterized. Thermogravimetric analysis demonstrated that the main frame of 1 exhibited good thermostability up to 473 K. The non-isothermal kinetics for the first exothermic process of 1 were studied by Kissinger and Ozawa methods. The magnetic study revealed that 1 possessed antiferromagnetic exchange interactions between CuII ions through the carboxyl-bridge. The low-temperature (1.9 to 300 K) heat capacity of 1 was measured using the heat-capacity option of a Quantum Design Physical Property Measurement System (PPMS). In addition, the thermodynamic functions in the experimental temperature range were derived by fitting the heat-capacity data to a series of theoretical and empirical models. The standard entropy and standard enthalpy of 1 were respectively calculated to be 411.37 ± 4.11 J mol-1 K-1 and 60.21 ± 0.60 kJ mol-1.
Read more16Heat capacity and thermodynamic functions of boehmite (AlOOH) and silica-doped boehmite
Heat capacity and thermodynamic functions of boehmite (AlOOH) and silica-doped boehmite
Copyright 2026 Cactus Communications. All rights reserved.
