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[Display omitted] • Slow evaporation synthesis method at room temperature of (C 6 H 7 N 2 S)NO 3. • Hybrid nitrate salt of 4-pyridinethioamide with a supramolecular crystal structure. • A good thermal stability for a wide range of temperatures. Organic-inorganic hybrid nitrate salt associating the aromatic organic molecule 4-pyridinethioamide with the (C 6 H 7 N 2 S)NO 3 formula was synthesized by slow evaporation method at room temperature. The obtained material is crystallized in the monoclinic system with the centro-symmetric space group P 2 1 / c. The supramolecular crystal structure was built from nitrate anions N O 3 - entities linked to the organic cations (C 6 H 7 N 2 S)+ by hydrogen bonds and weak interactions. Besides, the aromatic pyridinium rings of 4-pyridinethioamide molecules were proven to form chains through π...π interactions. The Hirshfeld analysis results have shown that in all potential molecular contacts, the H...O/O...H constitutes the most important interaction in the crystal with a contribution percentage of 39 %. The thermal behavior studied by thermogravimetric analyses revealed good stability up to 175 °C. Preliminary analyses recorded with infrared and Raman spectroscopy confirmed the existence of vibrational modes corresponding to the formation of the hybrid compound before performing the characterization by X-ray single-crystal diffraction. The optical absorption spectrum exhibits two bands located at 4.82 eV (257 nm) and 3.95 eV (314 nm), which can be even observed with the naked eye at room temperature and is due to exaction emission. [ABSTRACT FROM AUTHOR]

Cu 1.8 S has received a lot of interest as a prospective thermoelectric material with the best performance and abundant resources. While high charge carrier concentration contributes to the high electrical conductivity and power factor values, grain-boundary engineering is required to improve the phonon scattering and thermal stability of Cu 1.8 S. We used a simple process that combined nanoparticles via mechanical alloying and post-annealing to introduce the reduced graphene oxide (rGO) heterointerface into the Cu 1.8 S matrix. A significant enhancement of power factor has been realized that the highest power factor is 721 μWm−1 K−2 at 550 K in the composite Cu 1.8 S/rGO with 10 % rGO, which is higher than the pure Cu 1.8 S. Furthermore, following four cycles of testing from ambient temperature to 550 K, the composite demonstrated excellent repeatability of power factor, confirming its practical application potential. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Single-phase MgFe 2 O 4 nanoparticles (crystallite size ∼ 27 nm) were synthesized via citrate precursor route. • Saturation magnetization increased from ∼ 26.46 emu/g (300 K) to ∼ 34.79 emu/g (100 K). • Low coercivity (92–187 Oe) from 300 K to 100 K indicated soft magnetic behavior. • Observed remanent magnetization of ∼ 5.58 emu/g and remanence ratio of 0.21 at 300 K. • Blocking temperature estimated at ∼ 573 K, coercivity at 0 K at ∼ 249 Oe, and Curie temperature at ∼ 660 K. Low temperature magnetization measurements of citrate precursor-synthesized magnesium ferrite nanoparticles (MFNPs) of ∼ 27 nm were conducted by progressively lowering the temperature from 300 K to 100 K. Hysteresis curves revealed unsaturated magnetization even at ± 15 kOe, attributed to surface spins. Specific saturation magnetization (σ s) and coercivity (H c) experienced an increase from 26.46 emu/g (300 K) to 34.79 emu/g (100 K), and from 92 Oe (300 K) to 187 Oe (100 K), respectively. Specific remanence magnetization (σ r) rose from 5.58 emu/g (300 K) to 10.14 emu/g (100 K), indicating a notable shift in magnetic behavior. Effective anisotropy constant (K eff) showed significant growth from 2474.14 erg/g (300 K) to 6635.04 erg/g (100 K), highlighting low magnetocrystalline anisotropy at room temperature. The rise in magnetic moment (n B) from 0.95 Am2 at 300 K to 1.25 Am2 at 100 K indicates improved magnetic alignment and stability, particularly at lower temperatures. Correlation analysis revealed strong negative curvilinear correlations between magnetic properties and temperature. Extrapolation estimated the blocking temperature (∼573 K), coercivity at 0 K (∼249 Oe), and Curie temperature (∼660 K). These results suggest promising applications in space technology, underscoring the enhanced sensitivity of MFNPs to external magnetic fields in cold environments. [ABSTRACT FROM AUTHOR]

• New oxyfluoroniobate glasses were synthesized in the ZnNbOF 5 -BaF 2 -InF 3 system. • The thermal properties of the obtained glasses are determined. • The structures of the glass networks in the system studied are revealed. • Glasses in the ZnNbOF 5 -BaF 2 -InF 3 system show luminescence was properties. • In glasses with luminescent properties, nano-objects 9–13 nm in size were found. Glasses in the ZnNbOF 5 –BaF 2 –InF 3 and ZnNbOF 5 -BaF 2 systems were produced using the ZnNbOF 5 •6H 2 O compound. The structure, thermal and luminescent properties of the obtained glasses were studied with IR-, Raman, SAXS, luminescent spectroscopy methods, calorimetry and X-ray diffraction. The highest range of thermal stability and resistance of glass to crystallization has been established for the glass of 20ZnNbOF 5 –40BaF 2 –40InF 3 composition. This value is an order of magnitude higher than in glasses of the same system, but not containing InF 3. Glasses networks are formed from polyhedra of InF 6 , NbO 2 F 4 and NbO 3 F 3. For all glasses containing InF 3 , photoluminescence contribution which depends on the concentration of indium trifluoride in the glass was recorded. This contribution corresponds to the emission levels of 542, 573, 673, 751 nm. Luminescent properties are shown by glasses in which nanoobjects (nanoinhomogeneities) in size of 9-13 nm were detected by SAXS method. [ABSTRACT FROM AUTHOR]

Abstract MgO containing vanadate glasses of composition V 2- x Mg x O 5-δ (x = 0.05, 0.10, 0.15, 0.20, 0.25 and 0.30) have been prepared successfully by melt-quench technique. The structural properties of the as-quenched samples are explored with the help of X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. Thermal properties and conductivity of the samples are investigated using differential thermal analysis (DTA) and impedance spectroscopy, respectively. Density, inter-ionic distance, and fragility index are found to decrease with the addition of MgO content. Higher content of MgO improves the glass formation tendency and reduces the thermal stability of the samples. The conductivity of the V 2- x Mg x O 5-δ samples decreases as the MgO concentration increases due to hindrance in the polaronic conduction of vanadium ions. The conductivity of the samples decreases to ̴ 10−4 S m−1 for x = 0.30 at 300 °C, while activation energy increases to 0.38 eV. These samples may find application in solid state batteries and fuel cells due to their higher conductivity. [ABSTRACT FROM AUTHOR]

(a) The figure shows the Ba 3 MgTa 2 O 9 : x Sm3+ (0.01 ≤ x ≤ 0.15) CIE chromaticity coordinates, and the inset on the upper right corner shows the pictures of the Ba 3 MgTa 2 O 9 :0.05Sm3+phosphor samples under daylight and 265 nm lamp irradiation, respectively. (b) The graph shows the color purity of the Ba 3 MgTa 2 O 9 : x Sm3+ (0.01 ≤ x ≤ 0.15) phosphor sample. [Display omitted] • Ba 3 MgTa 2 O 9 :Sm3+ phosphors were firstly synthesized via a high-temperature solid-state reaction. • The phosphor emits bright orange-red light excited by 407 nm. • The phosphor exhibits good color stability and high color purity (98.51 %). • Ba 3 MgTa 2 O 9 :Sm3+ has good thermal stability and suitable color temperature, and is expected to be used in near-UV excited WLEDs. In this study, a Ba 3 MgTa 2 O 9 : x Sm3+ orange-red phosphor was synthesized by a high-temperature solid-phase reaction method, and its fluorescence properties were analyzed. The Ba 3 MgTa 2 O 9 : x Sm3+ phosphor exhibited three emission peaks at 561 nm (4G 5/2 → 6H 5/2), 595 nm (4G 5/2 → 6H 7/2), and 642 nm (4G 5/2 → 6H 9/2) under the excitation of 407 nm. The Ba 3 MgTa 2 O 9 :0.05Sm3+ phosphor had good thermal stability and excellent color stability at different temperatures. Ba 3 MgTa 2 O 9 :0.05Sm3+ phosphor is the best doping concentration phosphor, with a high color purity of 98.52 %. The XRD of the Sm3+ ion-doped phosphor showed that its crystal structure and morphology were stable, and the doping of Sm3+ ions did not affect its crystal structure significantly. Therefore, the Sm3+ ion-doped phosphors in this study have potential applications and are expected to be used in the field of WLED. [ABSTRACT FROM AUTHOR]

Quaternary Co 2 FeAl 0.5 Si 0.5 Heusler alloy thin films have attracted special attention for the application in magnetoelectronic devices. Co 2 FeAl 0.5 Si 0.5 alloy thin films are fabricated by magnetron sputtering at room temperature. The temperature effects on the magnetic, electrical and optical properties in sputtered Co 2 FeAl 0.5 Si 0.5 alloy films are investigated. Thermomagnetic measurements reveal increased magnetization arising from enhanced crystalline ferromagnetic ordering. Anomalous increase in electrical resistivity with temperature is probed in the alloy film, accompanied with significant change in optical reflectance. The large variations in electrical and optical signals in the alloy film can be attributed to the transition of atomic orderings, confirmed by X-ray diffraction measurements. The activation barrier for the transformation of atomic orderings is determined to be 1.22 eV, showing good thermal stability of the Heusler alloy thin film. [ABSTRACT FROM AUTHOR]

(Ba 1− x Bi 0.5 x Sr 0.5 x )(Ti 1− x Bi 0.5 x Sn 0.5 x )O 3 (BBSTBS, 0.02 ≤  x  ≤ 0.1) samples were prepared by a solid state reaction (SSR) method. The phase structure and dielectric properties of BBSTBS ceramics were investigated. X-ray diffraction results illustrated that BBSTBS could form a homogenous solid solution. Optimum properties with a stable ε r (∼13,643–19,000), small Δε/ε 25 °C values (±15%) over a broad temperature range from −61 °C to 210 °C and low tanδ (≤0.025) from −67 °C to 220 °C were obtained at x  = 0.06. [ABSTRACT FROM AUTHOR]

Conventional polyimide nanocomposites reinforced with graphene-based nanofillers usually possess excellent properties, such as high thermal decomposition temperature, enhanced tensile strength, tensile modulus, etc. However, the elongation at break of the nanocomposites is reduced. Here, we prepared N-doped graphene quantum dots/colorless polyimide nanocomposite (N-GQDs/CPI) films for the first time by in-situ polymerization, whose elongation at break is about 2 times that of the pure film. Meanwhile, the thermal properties and other mechanical properties of the films are improved. Through analyzing FT-IR, XPS, XRD, TAG SEM, etc. of N-GQDs and the films, we consider that the strengthening mechanism of matrix performance is attributed to N-GQDs' well dispersion, its small size effects and strong interface interaction with the matrix. Furthermore, at the indicative wavelength of 550 nm, the optical transmittance of the film with 1 wt% N-GQDs still maintains 79%, indicating the resulting films have excellent optical transmittance. The hydrophilic properties of the prepared films' surface is reduced, their water surface contact angle are increased from 63 ± 2.7° to 92 ± 1.7° with the content of N-GQDs increasing. This research shows that N-GQDs can enhance the various properties of polyimide and provides a high performance nanocomposite films for potential flexible substrates. [ABSTRACT FROM AUTHOR]

DC reactive magnetron sputtered Nb z Al y N x coatings with various Al contents ( y /( y + z )) ranging from 0 to 0.75 were deposited using different ratios of the currents applied to the Al and Nb targets in order to systematically control their chemical composition and crystalline structure, and to enhance their mechanical, tribological and thermal stability performance. The film microstructure and properties were assessed by various complementary techniques such as electron probe microanalysis, X-ray diffraction, nanoindentation, ball-on-disc test, and scanning electron microscopy. It was found that the solubility limit of Al in the NbN lattice is in the range 0.44 < y /( y + z ) < 0.60. The Nb z Al y N x coatings present low compressive residual stress (≤ 3 GPa), and their hardness increases up to 31 GPa with increasing y /( y + z ) up to 0.40. The observed hardening is attributed to the solid solution mechanism. For y /( y + z ) > 0.44, the hardness of the Nb z Al y N x coatings is reduced due to the formation of the soft hexagonal AlN phase. In addition, the coatings exhibit interesting tribological properties: the coefficient of friction is in the range of 0.74 to 0.85, and wear rate is in the range of 4.8–9.1 × 10 − 6 mm 3 /Nm. Thermal stability shows a dependence on the Al content; specifically, the Nb 0.33 Al 0.17 N 0.50 coating was found to be thermally stable up to 700 °C. [ABSTRACT FROM AUTHOR]

A new nitrogen-rich energetic salt, 2,4-diamino-6-methyl-1,3,5-triazine dinitramide, was synthesized by combining silver dinitramide and 2,4-diamino-6-methyl-1,3,5-triazine perchlorate. The structure of this new energetic salt was confirmed using single-crystal X-ray diffraction, elemental analysis, Fourier transform infrared spectrometry, ultraviolet–visible spectrophotometry, and nuclear magnetic resonance spectroscopy. The thermal stability was determined using differential scanning calorimetry, differential thermal analysis, and thermogravimetric tandem infrared spectrometry. Results showed that the target compound exhibits good thermal decomposition resistance of up to 470 K and has 59.1% mass loss with E a = 118.2 kJ mol −1 . Additionally, the detonation pressure and velocity obtained using Kamlet-Jacobs equations are 23 GPa and 8.2 km s −1 , respectively. Sensitivity test was also attempted. The impact sensitivity of this new energetic salt is 11.5 J, which is superior to that of RDX (7.4 J). [ABSTRACT FROM AUTHOR]

Three new complexes of 1,3-diethyl-thiobarbituric acid (HDetba), barbiturate-bridged 2D Mn(II) polymer [Mn(H 2 O) 2 (Detba) 2 ] ( 1 ), trinuclear [Mn 3 (H 2 O) 10 (Detba) 6 ] ( 2 ) and discrete molecular [Mn(H 2 O) 4 (Detba) 2 ]·H 2 O ( 3 ) are synthesized and structurally characterized by the X-ray single crystal technique. In 1 – 3 , the Detba − ions are coordinated to Mn(II) only through O atoms with manganese ions in the octahedral environment. In 1 , the Mn(II) ion is coordinated by four μ 2 bridge Detba − ions and two terminal H 2 O molecules. In 2 , the Mn1 ion is coordinated by three terminal H 2 O molecules, two terminal and one μ 2 bridge Detba − ion, and Mn2 is connected with two μ 2 -Detba − ions and four H 2 O molecules. In 3 , the Mn(II) ion is coordinated by two terminal Detba − ions and four terminal H 2 O molecules. There are intermolecular hydrogen bonds O–H⋯O, O–H⋯S in the structures of 1 – 3 which form the 3D networks. Structure 2 is stabilized by the π–π interaction. The compounds thermal decomposition comprises dehydration steps and the organic ligand oxidation. [ABSTRACT FROM AUTHOR]

Amorphous TbFeCo material with perpendicular magnetic anisotropy is currently attracting more attention for potential applications in spintronic devices and logic memories. We systematically investigate magnetic, structural, thermal, optical and electrical properties of TbFeCo alloy films. It shows out-of-plane easy axis of the films turns into in-plane orientation after annealing. Significant increase in saturation magnetization in the temperature range between 400 and 450 °C is revealed by thermomagnetic measurements. The occurrence of crystallization and oxidation at high temperatures is confirmed by X-ray diffraction measurements. Pronounced changes in optical reflectance and sheet resistance are observed with temperature, in line with structural relaxation and change. The activation barriers for crystallization and oxidation are determined to be 1.01 eV and 0.83 eV, respectively, for FeCo-rich and Tb-rich samples. Better thermal stability against crystallization and oxidation is demonstrated in the FeCo-rich sample than the Tb-rich type. Our results provide some useful information for the alloy used in device fabrication. [ABSTRACT FROM AUTHOR]

We present a detailed study of post-deposition annealing effects on contact resistance of Au, Ti, Hf and Ni electrodes on Mg 2 Si thin films. Thin-film Mg 2 Si and metal contacts were deposited using magnetron sputtering. Various post-annealing temperatures were studied to determine the thermal stability of each contact metal. The specific contact resistivity (SCR) was determined using the Cross Bridge Kelvin Resistor (CBKR) method. Ni contacts exhibit the best thermal stability, maintaining stability up to 400 °C, with a SCR of approximately 10 −2 Ω-cm 2 after annealing. The increased SCR after high temperature annealing is correlated with the formation of a Mg-Si-Ni mixture identified by cross-sectional scanning transmission electron microscopy (STEM) characterization, X-ray diffraction characterization (XRD) and other elemental analyses. The formation of this Mg-Si-Ni mixture is attributed to Ni diffusion and its reaction with the Mg 2 Si film. [ABSTRACT FROM AUTHOR]

The effects of hydrogen absorption on the structure, mechanical and thermal properties of Zr 57 Al 10 Cu 15.4 Ni 12.6 Nb 5 amorphous metal were investigated. Structural analysis, using X-ray diffraction, showed that prominent peak shift towards lower angles (from 37.55° to 37.47°) after 1 h of hydrogen charging in 0.1 M NaOH solution which indicates a volume expansion of the amorphous structure. By means of nanoindentation tests, we found that hydrogen-induced glass plasticity could occur in Zr-based metallic glass even for high Zr content (> 50 at.%). The thermal stability against crystallization, evaluated by differential scanning calorimetry (DSC), has been improved by hydrogen absorption. The onset crystallization temperature was increased by 6 °C to 10 °C due to slight hydrogen addition. The resistance to hydrogen embrittlement combined with high thermal stability gives rise to the possibility of the practical use of Zr 57 Al 10 Cu 15.4 Ni 12.6 Nb 5 amorphous alloy as a good metal membrane operating at temperatures below 400 °C. [ABSTRACT FROM AUTHOR]

The strategy for the conversion of an N atom to a C–NO 2 group leading to a "NH 2 –NO 2 –NH 2 " block was described to improve the detonation properties and the thermal stability of an energetic compound simultaneously. [Display omitted] • A strategy of molecular design was proposed to enhance the thermal stabilities. • The "NH 2 –NO 2 –NH 2 "-substituted 3 shows excellent detonation performances. • The relationship between structure and properties was comprehensively studied. Developing energetic compounds with high performances and good molecular stabilities is considered difficult due to its inherent contradiction. In this work, the strategy for the conversion of an N atom to a C–NO 2 group leading to a "NH 2 –NO 2 –NH 2 " block was described to improve the detonation properties and the thermal stability of an energetic compound simultaneously. Based on this strategy, the amino-nitro-amino-substituted nitramine 3 with a high density of 1.96 g cm−3 at room temperature was synthesized. In addition, another amino-nitro-substituted nitramine 9 was also prepared. The structures of 3 and 9 were confirmed by single-crystal X-ray diffraction. Compound 3 exhibits high detonation performances (V D : 8953 m s−1, P : 35.3 GPa) and a good thermal stability (T d : 223 °C), which are superior to RDX, suggesting its great application potentials. [ABSTRACT FROM AUTHOR]

A promising bio-based and biodegradable polybutyrolactam (PBY) fiber with health care function was prepared for the first time by dry-jet-wet spinning. As-prepared PBY fibers possesses the degree of crystallization upto 45.61%, appreciable thermal stability, excellent strength upto 2.1 cN•dtex−1, as well as good resistance to alkalis based on the results of X-ray diffraction, thermal and physical properties. The bio-degradability of PBY fibers were evaluated by the degraded behavior in soil, UV aging irradiation and seawater, showing commendable bio-degradation within 100 days. The analysis of the degradation based on TGA demonstrates that the removal of oligomers preferentially occurs, and then PBY macromolecules are broken. More interestingly, pharmaceutical γ -aminobutyric acid (GABA) is released during the degradation process, and it is beneficial to health care. As a biomass-derived and bio-degradable fiber, the sustainable PBY fiber exhibits an impressively competitive tensile strength among the existing degradable man-made fibers, showing great potential in bio-based fiber materials and health care textiles. [Display omitted] • Polybutyrolactam fiber was prepared for the first time by dry-jet-wet spinning. • The tensile strength of fiber reaches to 2.1 cN.•dtex−1. • Showing a commend bio-degradation performance within 100 days. • Pharmaceutical GABA is released during the degradation process. [ABSTRACT FROM AUTHOR]

In this work, in order to investigate the reinforcement effects of organic montmorillonite (OMMT) modified epoxy mortar binders (EMBs), a series of OMMT/EMB composites with different OMMT loadings were prepared. The structure and thermal stability of OMMT were studied by X-ray diffraction (XRD), Fourier transform infrared spectrum, and thermogravimetric analysis (TGA). The effects of OMMT on the structure, glass transition, damping properties, thermal stability, mechanical properties and morphology of EMB were characterized by XRD, dynamic mechanical analysis, TGA, tensile test, and scanning electron microscopy. XRD results indicated that epoxy chains intercalated into the OMMT layers and led to the expansion of OMMT layer spacing. The presence of OMMT increased the glass transformation temperature, crosslink density of the neat EMB. Furthermore, the incorporation of OMMT improved the thermal stability of the EMB. The OMMT/EMB composites showed higher tensile strength and Young’s modulus than the neat EMB. Homogenous dispersion of OMMT in EMB matrix was observed. [ABSTRACT FROM AUTHOR]

The thermal stability of FePdB thin films was studied using nonisothermal and isothermal analyses. X-ray diffraction (XRD) patterns indicated that Fe 40 Pd 40 B 20 and Fe 60 Pd 20 B 20 films with thicknesses in the range 25–75 Å were amorphous, whereas Fe 40 Pd 40 B 20 and Fe 60 Pd 20 B 20 films with thicknesses in the range 100–200 Å exhibited a nanocrystalline FePd (111) structure. The crucial glass forming ability index ( γ and γ m ) was determined using the differential scanning calorimetry (DSC) results of amorphous FePdB films. The Kissinger formula was applied to calculate the activation energy ( Q ) of crystallization for determining the resistance of the films to crystallization. Thermal analysis showed that the thermal stability and incubation time of Fe 40 Pd 40 B 20 are more favorable than those of Fe 60 Pd 20 B 20 . [ABSTRACT FROM AUTHOR]

Thermal stability is one of the critical requirements for commercial operation of high energy lithium-ion batteries. In this study, we use in situ X-ray diffraction technique to elucidate the thermal degradation mechanism of 0.5Li 2 MnO 3 -0.5LiNi 0.33 Co 0.33 Mn 0.33 O 2 lithium rich cathode material in the absence and presence of electrolyte to simulate the real life battery conditions and compare its thermal behavior with the commercial LiNi 0.33 Co 0.33 Mn 0.33 O 2 cathode material. We show that the thermal induced phase transformations in delithiated lithium rich cathode material are much more intense compared to similar single phase layered cathode material in the presence of electrolyte. The structural changes in both cathode materials with the temperature rise follow different trends in the absence and presence of electrolyte between 25 and 600 °C. Phase transitions are comparatively simple in the absence of electrolyte, the fully charged lithium rich cathode material demonstrates better thermal stability by maintaining its phase till 379 °C, and afterwards spinel structure is formed. In the presence of electrolyte, however, the spinel structure appears at 207 °C, subsequently it transforms to rock salt type cubic phase at 425 °C with additional metallic, metal fluoride, and metal carbonate phases. [ABSTRACT FROM AUTHOR]

Ethylene-vinyl acetate (EVA)/sepiolite nanocomposites were prepared by melt blending in a twin screw extruder. The structural, morphological, thermal, flammability and mechanical properties of the EVA/sepiolite nanocomposites were investigated using X-ray diffraction (XRD), Fourier transform infrared (FTIR), field emission scanning electron microscopy (FESEM), thermal analysis, tensile properties and limiting oxygen index (LOI) measurements. X-ray diffraction analysis and FESEM revealed good dispersion of sepiolite in EVA matrix. The tensile strength of EVA/sepiolite increased by 21% and Young's modulus increased by 47% at 5 wt% and 7 wt% sepiolite content, respectively. The thermal stability and fire retardancy of the nanocomposites improved with sepiolite incorporation. [ABSTRACT FROM AUTHOR]

Highlights: [•] Microcrystalline cellulose was successfully isolated from Alfa fibres. [•] The physicochemical and thermal properties were comparatively investigated and explained this finding. [•] Acid hydrolysis is a suitable method to produce microcrystalline cellulose. [•] Alfa-MCC can potentially be used for pharmaceutics, foods and green composites applications. [Copyright &y& Elsevier]

Structure and mechanical properties of the novel casting AJ62 (Mg–6Al–2Sr) alloy developed for elevated temperature applications were studied. The AJ62 alloy was compared to commercial casting AZ91 (Mg–9Al–1Zn) and WE43 (Mg–4Y–3RE) alloys. The structure was examined by scanning electron microscopy, x-ray diffraction and energy dispersive spectrometry. Mechanical properties were characterized by Viskers hardness measurements in the as-cast state and after a long-term heat treatment at 250°C/150hours. Compressive mechanical tests were also carried out both at room and elevated temperatures. Compressive creep tests were conducted at a temperature of 250°C and compressive stresses of 60, 100 and 140MPa. The structure of the AJ62 alloy consisted of primary α-Mg dendrites and interdendritic nework of the Al4Sr and massive Al3Mg13Sr phases. By increasing the cooling rate during solidification from 10 and 120K/s the average dendrite arm thickness decreased from 18 to 5μm and the total volume fraction of the interdendritic phases from 20% to 30%. Both factors slightly increased hardness and compressive strength. The room temperature compressive strength and hardness of the alloy solidified at 30K/s were 298MPa and 50 HV 5, i.e. similar to those of the as-cast WE43 alloy and lower than those of the AZ91 alloy. At 250°C the compressive strength of the AJ62 alloy decreased by 50MPa, whereas those of the AZ91 and WE43 alloys by 100 and 20MPa, respectively. The creep rate of the AJ62 alloy was higher than that of the WE43 alloy, but significantly lower in comparison with the AZ91 alloy. Different thermal stabilities of the alloys were discussed and related to structural changes during elevated temperature expositions. [ABSTRACT FROM AUTHOR]

Abstract: In the present study, our main motivation was to investigate the structural and thermal stability of BN nanoparticles (B1.0N0.9-NPs) produced by spray-pyrolysis (SP) of borazine at 1400°C by thermogravimetric experiments and X-ray diffraction. We observed that B1.0N0.9-NPs are relatively stable in air below 850°C in which only oxidation of the NP surface proceeded. Above 850°C, the powders started to strongly react with air due to bulk oxidation. Under nitrogen, they appeared to be less stable than plate-like BN synthesized from borazine at 1400°C through conventional pyrolysis. This is related to the low degree of crystallization of B1.0N0.9-NPs that clearly affects their stability. Using a post-pyrolysis treatment at 1400°C, B1.0N0.9-NPs remained stable up to 1600°C similarly to plate-like BN. However, above 1600°C, a relatively fast weight loss occurred for B1.0N0.9-NPs, whereas plate-like BN remained stable up to 1800°C. This indicated that their lower size also affects their high temperature thermal behavior. [Copyright &y& Elsevier]

Abstract: Li1.11(Ni0.40Mn0.39Co0.16Al0.05)0.89O2 was synthesized through coprecipitation of a mixed hydroxide followed by calcination with LiOH·H2O during 10h at 500°C and 950°C. Electrochemical tests and their comparison with those obtained for an industrial Li(Ni1−y−z Co y Al z )O2 material reveal that Li1.11(Ni0.40Mn0.39Co0.16Al0.05)0.89O2 shows good charge–discharge performance, even at high rate according to a protocol well established by car-makers for testing power abilities of batteries for electric and hybrid electric vehicles. In addition, this material shows a significant improvement in thermal stability in the highly deintercalated state (charged state of the battery) over the industrial material. Equivalent (or higher) energy and power densities with a significantly greater thermal stability make of Li1.11(Ni0.40Mn0.39Co0.16Al0.05)0.89O2 an interesting candidate as positive electrode material for large lithium-ion batteries. [Copyright &y& Elsevier]

Abstract: A novel series of Ge–Te–BiI3 chalcogenide glasses were prepared by traditional melt-quenching method and the glass-forming region was determined. Properties measurements including density, Vis–NIR and infrared (IR) transmission spectra with FTIR, XRD, DSC were adopted to analyze the composition, structure and performance of the Ge–Te–BiI3 glass system. Based on the metallization criterion and band gap energy theory, the relationships between energy gap, metallization criterion and glass composition was investigated. The results show that with the addition of BiI3, the glasses-forming ability and thermal stability are improved. The values of energy band gap and metallization criterion are within the range of 0.627–0.343eV and 0.177–0.131, respectively. These series of glasses have wide optical transmission window from 2.2 to 25μm and can offer an alternative solution for far infrared transmitting applications. [Copyright &y& Elsevier]

Abstract: The effect of layered silicate nanoclays, nano-silica and double-walled carbon nanotubes (DWNTs) on the thermal stability and fire reaction properties of two aerospace grade epoxy resins (a high temperature curing tetra-functional and a low temperature curing bi-functional resin) has been investigated using thermal analysis, cone calorimetry, LOI and UL-94 techniques. The morphology of the polymer–clay nanocomposites, determined by X-ray diffraction and transmission electron microscopy indicated intercalated structures. The addition of nanoclays (5-wt%) to both resins had a thermal destabilisation effect in the low temperature regime (<400 °C), but led to higher char yield at higher temperatures. The inclusion of nano-silica at 30-wt% significantly improved the thermal stability of the resins while DWNTs had an adverse effect due to their poor dispersion in the matrix. The nanoclays and carbon nanotubes significantly increased the fire resistance of the tetra-functional epoxy resin while a minimal effect was observed for the bi-functional resin. [Copyright &y& Elsevier]

Abstract: Cu7Te4 nanoparticles and sheet-like particles have been successfully synthesized using different organic solvents (acetone and cyclohexanone) by a solvothermal process. X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) were employed to characterize the as-obtained products. From the experimental results, it has been revealed that the reaction temperature and types of organic solvent have crucial effects on the morphology of the prepared products. The possible formation mechanism for diverse microstructures was put forward. Furthermore, the oxidation process of Cu7Te4 nanoparticles and sheet-like particles under air indicates morphology-dependent property. [ABSTRACT FROM AUTHOR]

Abstract: The role of electron-beam modified atactic polypropylene (aPP) as a compatibilizer for non-polar aPP and polar nanoclay was studied. aPP was modified at room temperature with high-energy electrons at 200kGy in an air atmosphere under reactive conditions (with an average dose rate of 10kGy/h). FTIR studies showed the generation of specific polar functional groups in reactive electron-beam modified aPP compared to unreacted aPP. The modified aPP was used as a compatibilizer in non-polar aPP and organically modified montmorillonite (MMT). The addition of modified aPP improved the dispersion of MMT in the aPP matrix, as indicated by XRD, SEM, and TEM studies. The thermal properties were also improved which further supported better dispersion of modified MMT in aPP matrix due to compatibilizing action of reactive electron-beam modified aPP. [Copyright &y& Elsevier]

Abstract: The thermal expansion and stability of predominantly single-phase Ti2SC powders in argon and air was investigated by Rietveld analysis of synchrotron X–ray diffraction spectra. When the sample was heated in an Ar atmosphere, it started to dissociate into TiS2 (see footnote 1) at ≈400°C. At 8.5 (5)×10−6 °C−1 and 8.8 (2)×10−6 °C−1 the thermal expansion coefficients along the a and c-directions, respectively, are quite similar. The volumetric thermal expansion is 25.2 (5)×10−6 °C−1. When Ti2SC was heated in air, it started to oxidize, at 400°C, first to anatase, which converts, at higher temperatures, to rutile. The sulfur and carbon atoms presumably diffuse outward and escape as gases. [Copyright &y& Elsevier]

Abstract: A synergistic effect was observed between montmorillonite and a novel intumescent flame retardant, poly (4, 4-diaminodiphenyl methane spirocyclic pentaerythritol bisphosphonate) (PDSPB) in ABS nanocomposites. Montmorillonite dispersion was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Thermal stability and flammability properties were investigated by thermogravimetric analysis (TGA) and cone calorimeter tests. Incorporating PDSPB together with montmorillonite enhanced thermal stability and flame retardancy of the ABS resin. The synergistic mechanism is caused by formation of silicoaluminophosphate (SAPO) structure formed by reactions between the phosphoric acid generated on heating from PDSPB and montmorillonite. Decomposition of the alkylammonium ion yields strongly acidic catalytic sites that may promote the oxidative dehydrogenation crosslinking charring process and increase the char yield. Silicoaluminophosphate was characterized by FT-IR spectrometry and field emission scanning electron microscopy. [Copyright &y& Elsevier]

Abstract: Amorphous and nanocrystalline phases generated in an elemental blend of Al94.5Cr3Co1.5Ce1 composition (at.%) in the course of mechanical alloying (MA) have been investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and differential scanning calorimeter (DSC). It has been reported that rapid solidification processing (RSP) of the same composition generates a finely mixed unique structure consisting of nanoscale icosahedral (I) particles surrounded by a thin Al phase [A. Inoue, Nanostruct. Mater. 6 (1995) 53–64]. In contrast, MA of Al94.5Cr3Co1.5Ce1 composition carried out in the present study shows the formation of Al-based solid solutions along with partial amorphisation. It emerges that during MA a wide difference in the atomic size of the alloying elements in solid solution plays a pivotal role in the amorphous phase formation. The possible causes of the difference in microstructure generated by MA and RSP have been discussed. The thermal stability of the mechanically alloyed product has also been investigated by a differential scanning calorimeter (DSC) and XRD. [Copyright &y& Elsevier]

• The effect of Mn additions on the structural and magnetic properties of AlCoCrFeNi was studied. • The arc-melted alloys consisted of a mixture of B2 and bcc phases, the relative amount of which was dependent on Mn content. • Gas atomised powders were single phase with the B2 structure. • Mn additions increased saturation magnetisation but lowered the magnetic transition temperature and the thermal stability. ga1 Alloys of AlCoCrFeMn x Ni (x = 0.0, 0.04, 0.08, 0.12 and 0.16) have been synthesized through arc–melting and gas atomisation (x = 0.0 and 0.16) to investigate the effect of Mn additions to AlCoCrFeNi. Here, the structure, magnetic properties and the thermal stability of the alloys is presented. Electron microscopy confirmed the elemental composition and revealed the microstructure to consist of two spinodally decomposed phases. Rietveld analysis of standard powder X-ray diffraction showed the arc-melted samples consisted of two phases, a B2 phase and a bcc phase while the gas atomised powders consisted of a single-phased B2 structure. Magnetic measurements revealed an increase in the saturation magnetisation at room temperature by 68% for AlCoCrFeMnNi compared to AlCoCrFeNi. The thermal stability of the alloys was investigated using magnetometry, differential scanning calorimetry and in–situ X-ray diffraction, which showed that an increase in Mn content adversely effected the thermal stability of the alloy. [ABSTRACT FROM AUTHOR]

In this manuscript the crystal structure of Li 3 UF 7 from powder X-ray and neutron diffraction studies is reported. The existence of Li 3 UF 7 has been debated for a long time, as it is often missed in a number of phase diagram studies. This study adopted a judicious composition of LiF and UF 4 , and an optimum cooling rate to prepare Li 3 UF 7. The Li 3 UF 7 phase could be obtained by cooling the molten LiF-UF 4 with large excess of LiF at a rate of 5 K/min while slower cooling tends to form LiUF 5. The crystal structures of Li 3 UF 7 and LiUF 5 in the temperature range of 300–10 K have been obtained from the powder neutron diffraction studies. At 300 K, Li 3 UF 7 has an orthorhombic lattice with unit cell parameters: a = 8.698(2) Å, b = 8.692(2) Å, c = 12.803(1) Å, V = 968.0(4) Å3; Z = 8 (Space group: C cca), and is isostructural to orthorhombic Li 3 ThF 7. On cooling, the orthorhombic distortion of Li 3 UF 7 increases but does not reveal any structural transition down to 10 K. The crystal structure of Li 3 UF 7 is built from the defective (Li-deficient) layers of edge shared octahedral LiF 6 and layers corner connected UF 9 polyhedra. Analogous studies on LiUF 5 have also been carried out, which has a tetragonal (Space Group: I 4 1 /a) lattice with unit cell parameters: a = 14.8882(8) Å, c = 6.5438(7) Å, V = 1450.5(2) Å3; Z = 16. The structure of LiUF 5 is built from the three-dimensional sub -lattice formed by U 4 F 30 units and the empty tunnels of the sublattice are occupied by Li 4 F 16 clusters formed by four edge shared LiF 6 octahedra. Also, the details of crystal chemistry of the compounds in LiF-UF 4 systems and their thermal stabilities are discussed. The complexity in the crystal chemistry in LiF-UF 4 system is manifested in multiple close by thermal events in the DTA runs which has also been discussed in the manuscript. ga1 • Synthesis and crystal structure of metastable Li 3 UF 7 in LiF-UF 4 are reported. • Conditions for formation of different phases in LiF-UF 4 system are delineated. • Crystal structures of Li 3 UF 7 and LiUF 5 down to 5 K are studied by LT-PND. • Anisotropic thermal expansion in Li 3 UF 7 is observed in between 5 and 300 K. • LiF-UF 4 phase diagram and comparative crystal chemistry phases in it are discussed. [ABSTRACT FROM AUTHOR]

• The high-energy 3,5-dinitro-4-oxyl-pyrazolate ligand were adopted to successfully construct three new energetic coordination compounds (ECCs). • The as-prepared materials exhibit excellent thermal stability (T d > 290 °C) and low sensitivity (IS = 14–18 J, FS = 240–324 N). • This work provides new inspiration for the development of novel green ECCs. In recent years, the discovery of novel energetic coordination compounds (ECCs) with high energy performance and low sensitivity is very desirable but highly challenging. Nitroazole-based ECCs have attracted a lot of attention in this area owing to their prominent advantages including excellent energy performance and good thermostability. Herein, three new ECCs based on 3,5-dinitro-4-oxylpyrazolate (DNOP) ligand were synthesized, characterized and evaluated as potential high-energy materials. Their structures and coordination mode were confirmed by the single crystal X-ray diffraction analysis. Thermal stability, sensitivities and energy performance were measured and studied in detail. The results suggest that as-prepared new ECCs are classified as "less sensitive" energetic materials exhibiting relative low sensitivity (IS = 14–18 J, FS = 240–324 N). Additionally, these new ECCs exhibit excellent thermal stability with high decomposition temperature beyond 290 °C. Inheriting the significant energy performance of 3,5-dinitro-4-oxylpyrazolate ligand, they could also possess attractive energy property. [ABSTRACT FROM AUTHOR]

• Two Strandberg type phosphomolybdates anions with different organic counterions are synthetized. • As the non-protonated anion is more prone to be reduced, we show through the analysis of the two compounds and the literature that the selection of the precursors may be crucial for the stabilization of the suitable anion. • Thermal and electrochemical properties were also investigated. Strandberg-type phosphomolybdate anions are metal-oxide clusters with general formula [H n P 2 Mo 5 O 23 ](6−n)− (n = 0, 1, 2). The protonation/deprotonation of this anion affects its redox properties. Herein, we explain how to select the organic counterions to direct the synthesis towards the non-protonated or protonated anion. The method is illustrated with the synthesis of two new compounds (C 5 H 16 N 2) 3 [P 2 Mo 5 O 23 ]·4H 2 O (1) and (CH 6 N) 4 [H 2 P 2 Mo 5 O 23 ].CH 5 N·4H 2 O (2). The two compounds were characterized by UV–Visible absorption, IR spectroscopy and single crystal X-ray diffraction. Their thermal stabilities and redox properties were also investigated. [ABSTRACT FROM AUTHOR]

Single-composition Ba 2 YAlO 5 : Eu3+ (BYAO: Eu) red luminescent phosphor were prepared through high temperature solid-state reaction. The crystal structure and luminescence properties were studied via X-ray diffraction and photoluminescence spectra. Upon 468 nm excitation, the main emission peaks of BYAO: Eu phosphors locate in the 582, 591, 614 and 705 nm, corresponds to the 5D 0 →7F J (J = 0–3) conversion of Eu3+ ions. In Eu3+ singly doped BYAO phosphor, the optimum doping concentration and transfer distance was 20 mol%, 11.16 Å, respectively. Under 468 nm excitations, the phosphors of BYAO: Eu showed obvious thermal quenching properties and the 473 K luminescence intensity was 74.4% of 298 K. Moreover, the CIE chromaticity coordinate range from yellow-green to red through changing the concentration of Eu3+ ions, and calculated value of purity is 96.4%. it indicates that BYAO: Eu phosphor is potentially promising material for commercial red phosphors. • Phosphor energy transfer is between the nearest neighbor ions. • Eu3+-O2- charge transition band appeared redshifted. • Phosphors have obvious thermal quenching properties. • The color coordinates of phosphors range yellow-green from red. • Color purity of Ba 2 YAlO 5 : 0.2Eu3+ phosphor is calculated to be 96.6%. [ABSTRACT FROM AUTHOR]