Thermal Stability and Memory Characteristics of HfON Trapping Layer for Flash Memory Device Applications

This work focused on the study of thermal properties and kinetic behavior of LDPE- nanoclay composite films. The effect of nanoclay content (0.5, 1, 3, and 5 wt%) on thermal stability and crystallization characteristics of the nanocomposites were investigated by Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). The results from endothermic curve showed that the nanoclay played an important role in the crystallization of nanocomposites by acting as nucleating agent. From exothermic curve, there was a crystallization temperature shift which was attributed to crystallization process induced by nanoclay. The TGA results showed that the addition of nanoclay significantly increased the thermal stability of LDPE matrix, which was likely due to the characteristic of layered silicates/ clays dispersed in LDPE matrix as well as the formation of multilayered carbonaceous- silicate char. A well-known Coats- Redfern method was used to evaluate the decomposition activation energy of nanocomposite. It was demonstrated that introducing of nanoclay to LDPE matrix escalated the activation energy of nanocomposite decomposition resulting in thermal stability improvement.

To investigate the coercivity, corrosion resistance, and thermal stability of Nd–Fe–B magnets, their properties were investigated at room and high temperature before and after doping with Dy80Ga20 (at.%) powder. The coercivity of the magnets increased from the undoped value of 12.72 kOe to a doped value of 21.44 kOe. A micro-structural analysis indicates that a well-developed core-shell structure forms in the magnets doped with Dy80Ga20 powder. The improvement in magnetic properties is believed to be related to the refined and uniform matrix grains, continuous grain boundaries, and a hardened (Nd, Dy)2Fe14B shell surrounding the matrix grains. Additionally, the doped magnets exhibit an obvious improvement in thermal stability. For the magnets with added Dy80Ga20 powder, the temperature coefficients of remanence (α) and coercivity (β) increased to −0.106% °C−1 and −0.60% °C−1 over the range 20–100 °C, compared to temperature coefficients of −0.117% °C−1 (α) and −0.74% °C−1 (β) in the regular magnets without Dy80Ga20 powder. The irreversible loss of magnetic flux (Hirr) was investigated at different temperatures. After being exposed to 150 °C for 2 h, the Hirr of magnets with 4 wt.% Dy80Ga20 decreased by ∼95% compared to that of the undoped magnets. The enhanced temperature coefficients and Hirr indicate improved thermal stability in the doped Nd–Fe–B magnets. The intergranular addition of Dy80Ga20 also improved the corrosion resistance of the magnets because of the enhanced intergranular phase. In a corrosive atmosphere for 96 h, the mass loss of the sintered magnets with 4 wt.% Dy80Ga20 was 2.68 mg/cm2, less than 10% of that suffered by the undoped magnets (28.1 mg/cm2).

We designed and synthesized two novel blue pyrrole derivatives, 2-(3-cyano-4-(4-(dibutylamino)phenyl)-5-oxo-1,5-dihydro-2H-pyrrol-2-ylidene)malononitrile (BAPCP) and 2-(3-cyano-4-(4-(dihexylamino)phenyl)-5-oxo-1,5-dihydro-2H-pyrrol-2-ylidene)malononitrile (HAPCP), as potential candidates for use in image sensor color filters. The properties of these new compounds were evaluated, focusing on their optical and thermal characteristics in solution and color filter film forms. The molar extinction coefficient values of BAPCP and HAPCP in solution were 6.03 × 104 and 6.91 × 104 L/mol·cm. The molar extinction coefficient of HAPCP was 4.5 times higher than that of the commercially used Disperse Blue 359. The synthesized compounds exhibited transmittance values that meet commercial requirements, with 88.6% at 450 nm and 0.73% at 530 nm. Both newly synthesized compounds met the decomposition temperature requirement of over 230 °C, which is necessary for the manufacturing process of image sensor color filters. The decomposition temperatures of both compounds were approximately 19 °C higher than that of Disperse Blue 359. When the thermal stability of color filter films for image sensors was evaluated, BAPCP demonstrated excellent optical properties before and after thermal stability testing, maintaining its characteristics in an optimized molecular form. Accordingly, BAPCP appears to have favorable potential as a blue colorant for image sensors, attributed to its superior optical and thermal stability characteristics.

The consumption of synthetic, non-biodegradable polymer plastics has drawn attention to growing environmental concerns, prompting the development of other materials, particularly bio-based materials. Biopolymer-based biocomposite materials are plasticized to improve their ductility. In this study, five distinct weight ratios of biopolymers (PA/EOO), 90 wt.%, 80 wt.%, 70 wt.%, 60 wt.%, and 50 wt.% were employed as plasticizers for poly-lactic acid (PA) in a fluid molding process. The mechanical, thermal stability, and morphological characteristics of the blends were each examined using a viscometer measurement (R.V.), tensile properties (TP), a scanning electron microscope (SEM), and a thermogravimetric analyzer (TGA). All composite materials (PA/EOO) mixtures show notable improvements in mechanical properties and excellent thermal stability when compared to pure PA. The maximum PA/EOO elongation at break was around 213 % when the PA/EOO mix was 80 wt %. Attractive morphological results from composite materials (PA/EOO) blends showed that EOO was compatible with PA and that the resulting composite material (PA/EOO) was thought to be an ecologically beneficial mixture because it contained vegetable oil.

A study has examined the effect of mixing methods on the thermal stability and detonation characteristics of ammonium nitrate (AN) and sodium chloride (NaCl) mixtures. NaCl was mixed with AN by two methods. The thermal stability, detonation velocity and structural properties were investigated by differential scanning calorimetry (DSC), measurement of detonation velocity and X‐ray diffraction (XRD). For the mechanical mixing method, in all tested scope of proportions of NaCl in the mixtures, activation energies increase when the proportion of NaCl increases; for solution mixing method, the activation energies decrease first and then start to increase as the proportion of NaCl increases. The detonation velocity of AN‐NaCl mixtures prepared by two mixing methods also showed different results. The results indicate that the mixing methods significantly affect the thermal stability and detonation characteristics of AN.

Studies on the thermal stability and decomposition kinetics of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide via density functional theory and experimental methods

Thermal stability study of n-type and p-type ohmic contacts simultaneously formed on 4H-SiC

The thermal decomposition and heat transfer characteristics of gaseous, high-purity methane, several methane–hydrocarbon mixtures, and a typical natural gas fuel were evaluated using an electrically heated, stainless-steel tube test apparatus. Of several candidate heat transfer correlations, the Dittus–Boelter heat transfer correlation provided the best fit of the methane heat transfer data over the range of Reynolds numbers 10,000 to 215,000. The thermal stability (i.e., deposit formation) characteristics of the methane–hydrocarbon mixtures and the natural gas fuel were established and compared with the deposition characteristics of high-purity methane. Testing was conducted at wall temperatures up to 900 K (fuel temperatures to 835 K) for durations of up to 60 hours. Measurements of deposit mass indicated that there was essentially no deposit buildup for wall temperatures below 650 K. Deposit began to form at wall temperatures between 650 K and 775 K. Above 775 K, there was a rapid monotonic increase in deposition. The data suggest that the use of high-purity methane instead of natural gas at temperatures above 775 K could reduce the deposit thickness under similar operating conditions by as much as a factor of three, or permit operation at correspondingly higher temperatures.

Inhibition effect of ammonium dihydrogen phosphate on the thermal decomposition characteristics and thermal sensitivity of ammonium nitrate

The effectiveness of direct absorption solar collectors (DASCs) is limited due to the low photothermal conversion efficiency and poor heat transfer qualities of traditional fluids. One potential solution to address this problem is the development of innovative technologies to enhance the solar absorption ability and thermal conductivity of conventional fluids. New generation nanofluids where nanosized particles are dispersed in base fluids like water or ethylene glycol (EG) have attracted interest within diverse solar technologies owing to their superior optical and thermal properties. This study presents a novel TiO2/FeVO4/Ethylene glycol (TFV/EG) nanofluid which exhibits significant solar absorption and thermal stability characteristics. A thorough characterization of the samples was conducted utilizing X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Raman Spectroscopy, High-Resolution Transmission Electron Microscopy (HRTEM), nitrogen adsorption-desorption isotherms and Thermogravimetric Analysis (TGA). The stability, optical and rheological characteristics of TFV nanofluids were also examined. The study’s outcomes indicated that the integration of TFV nanoparticles into ethylene glycol (EG) markedly improved its optical absorption, especially at a concentration of 0.8 g/l TFV, which demonstrated robust absorption in the UV-visible light spectrum. Long-term stability assessments indicated sedimentation for all TFV concentrations following 65 days. A substantial 270% enhancement in thermal conductivity in comparison to EG base fluid was noted at 0.8 g/l TFV reaching 0.83 W·m⁻¹·K⁻¹. All nanofluids exhibited shear-thinning behavior, a hallmark of non-Newtonian fluids. The suggested TFV/EG represents a notable category of nanofluids that exhibited improved thermal performance and stability, rendering them very advantageous for efficient DASCs.

The lack of thermal and storage stability and occurrence of side reactions during the processing of 5-hydroxymethylfurfural (5-HMF) limits its potential as biorenewable platform molecule. The addition of small amounts of the readily available sodium dithionite has a remarkable effect on promoting the stability of 5-HMF and inhibiting side reactions, thus helping to circumvent such limitations. The addition of sodium dithionite led to improvements in thermal stability (120 °C, 4 h, neat; 100 % vs. 37 %), under distillation (yield: 85 % vs. 52 %), and in a wide range of reactions, including 5-HMF synthesis under biphasic conditions (yield: 98 % vs. 67 %; purity: 92 % vs. 83 %) and 5-HMF transformations, such as Knoevenagel condensation with Meldrum's acid (yield: 96 % vs. 74 %), Cannizaro reaction (yield: quantitative vs. 83 %), and condensation with primary diamines to give pyridinium salts (yield: 88 % vs. 60 %).

Magnesium hydroxide (MH) and alumina trihydrate (ATH) are extensively consumed as fillers in polyolefins to fabricate naturally responsive cables. Halogen-free wires, and especially cross-linked or thermoplastic elastomers, are further prevalent in worldwide use. The limited oxygen index (LOI), cone calorimeter, smoke density and thermogravimetry (TGA) experiments explain the thermal decomposition, flame-retardant and physical characteristics of samples. Results from studies of TGA, smoke emission and LOI testers showed that the thermal strength and flame-retardant characteristics of the samples containing MH compared with corresponding specimens containing ATH have superior thermal stability. The flame-retardant and heat resistance characteristics of samples were improved due to irradiation and the development of cross-linking bonds in the polymer framework. The results of the smoke density experiment show that adding MH to low-density polyethylene (LDPE) results in the lowest smoke density associated with LDPE and LDPE/ATH compounds. This study proved that the inclusion of MH and irradiation of specimens caused a greater thermal strength and also a superior flame-retardant polymeric product compared with the inclusion of ATH to similar irradiated specimens. These successes are useful and appropriate specifically for cable companies to deliver halogen-free flame-retardant cable materials.

Investigation on thermal reliability and corrosion characteristics of glutaric acid as an organic phase change material for solar thermal energy storage applications

The conventional hydroxyl-terminated polybutadiene (HTPB) hybrid fuel exhibits a slow regression rate which hindered their potential applications. Paraffin-based fuels regress considerably faster than HTPB fuel. Adding paraffin to HTPB could upgrade the regression rate and mechanical performance of a hybrid rocket. In the current study, the thermal decomposition and combustion characteristics of pure HTPB, pure paraffin, HTPB blended with 25, 40, 60, and 80% paraffin were prepared and analyzed. The surface morphology and chemical composition of HTPB-paraffin based fuels were investigated using Scanning Electron Microscope (SEM) and Fourier Transform Infrared Spectroscopy (FTIR), respectively. The thermal stability and combustion characteristics of HTPB-paraffin based fuels were examined using thermogravimetry (TG) analysis and differential scanning calorimetry (DSC) under an oxygen environment. The TG analysis revealed that the thermal stability of fuels decreased with increasing the weight percentage of paraffin in the composition. The TG/DTG results showed that HTPB-paraffin blends ignition and burnout temperatures decreased with increasing the concentrations of paraffin. Finally, the heat of combustion of tested fuels was evaluated using an isothermal oxygen bomb calorimeter. The combustion enthalpy of pure HTPB sample exhibited a value of 35.3 MJ g−1 and 46.2 MJ g−1 for pure paraffin sample. The results revealed that the addition of paraffin in HTPB increased the combustion enthalpy of blended samples.

The effects of both the degree of grafting and γ irradiation on the thermal stability and structural characteristic of polypropylene‐graft‐polyvinylpyrrolidone and polypropylene‐graft‐polyvinylpyrrolidone modified with α‐cyano‐δ‐(2‐thienyl) crotononitrile were investigated. The employed techniques were thermogravimetric analysis, differential thermogravimetry, and X‐ray diffraction. The thermal stability of various polymeric substrates was investigated through the determination of the degradation temperature and activation energy of degradation. The effects of different parameters on the structural characteristics of different films were investigated through the determination of possible changes in the degree of ordering of the polymeric substrates. The results revealed that the thermal stability of the trunk polymer, grafted polymer, and polymer modified by α‐cyano‐δ‐(2‐thienyl) crotononitrile increased progressively with an increasing degree of grafting. The increase was, however, more pronounced for the sample undergoing the lowest degree of grafting. The activation energy of the thermal degradation process remained almost unchanged, and this indicated that the degradation processes of the different films followed almost the same mechanism. The γ irradiation at a dose of 60 kGy of the sulfur‐treated polymeric films [i.e., the polymeric films treated with α‐cyano‐δ‐(2‐thienyl) crotononitrile] reduced their thermal stability. This conclusion was reached by the consideration of the changes observed in the pre‐exponential factor of the Arrhenius equation due to different chemical and γ‐irradiation treatments. The degree of ordering, evidenced by X‐ray diffraction measurements of the trunk polymer, grafted polymer, and modified polymer, suffered a significant drop. This drop was much more pronounced for the sulfur‐containing polymeric materials. The observed drop in the degree of ordering of the polymeric substrates was taken as a measure of the structure collapse due to a certain treatment (degree of grafting and sulfur inclusion). The γ irradiation of the sulfur‐containing polymeric materials greatly increased their degree of ordering, which reached a value greater than that measured for the trunk polymer. Therefore, it was concluded that the thermal stability increased as the degree of ordering decreased. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 506–515, 2006