scholarly journals Synchrotron Based Measurement of the Temperature Dependent Thermal Expansion Coefficient of Ammonium Perchlorate

2019 ◽  
Vol 45 (3) ◽  
pp. 480-485 ◽  
Author(s):  
Robert Kellogg ◽  
Saul Lapidus ◽  
Trevor Hedman ◽  
Joseph Kalman
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Ammonium Perchlorate ◽  
Expansion Coefficient ◽  
Temperature Dependent

Size- and temperature-dependent Young's modulus and size-dependent thermal expansion coefficient of thin films

2016 ◽  
Vol 18 (31) ◽  
pp. 21508-21517 ◽  
Author(s):  
Xiao-Ye Zhou ◽  
Bao-Ling Huang ◽  
Tong-Yi Zhang
Keyword(s):  
Thin Films ◽  
Thermal Expansion ◽  
Young’S Modulus ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Material Properties ◽  
Essential Role ◽  
Young's Modulus ◽  
Temperature Dependent ◽  
Size Dependent

Surfaces of nanomaterials play an essential role in size-dependent material properties.

scholarly journals Volumetric Properties in the NaAsO2 + H2O System at Temperature from 283.15 to 363.15 K and Atmospheric Pressure

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Hongfang Hou ◽  
Wanjing Cui ◽  
Jiaojiao Chen ◽  
Lingzong Meng ◽  
Yafei Guo ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Molar Volume ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Apparent Molar Volume ◽  
Correlation Coefficients ◽  
Apparent Molar Volumes ◽  
Temperature Dependent ◽  
Molar Volumes ◽  
Experimental Values

Densities of sodium arsenite (NaAsO2) aqueous solution with the molality varied from 0.19570 to 1.94236 mol·kg−1 at temperature intervals of 5 K from 283.15 to 363.15 K and 101 ± 5 kPa were measured by a precise Anton Paar Digital vibrating-tube densimeter. Apparent molar volumes (VΦ) and thermal expansion coefficient (α) were obtained on the basis of experimental data. The 3D diagram of apparent molar volume against temperature and molality and the diagram of thermal expansion coefficient against molality were generated. According to the Pitzer ion-interaction equation of the apparent molar volume model, the Pitzer single-salt parameters (βM,X0υ, βM,X1υ, βM,X2υ, and CM,Xυ, MX = NaAsO2) and their temperature-dependent correlation F(i, p, T) = a1 + a2ln (T/298.15) + a3(T − 298.15) + a4/(620 − T) + a5/(T − 227) (where T is temperature in Kelvin and ai are the correlation coefficients) for NaAsO2 were obtained for the first time. The predictive apparent molar volumes agree well with the experimental values, and those results indicated that the single-salt parameters and the temperature-dependent formula are reliable.

scholarly journals Thermal expansion coefficient of few-layer MoS2 studied by temperature-dependent Raman spectroscopy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhongtao Lin ◽  
Wuguo Liu ◽  
Shibing Tian ◽  
Ke Zhu ◽  
Yuan Huang ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Negative Thermal Expansion ◽  
Thermal Parameter ◽  
Temperature Dependent ◽  
Bending Vibrations ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients

AbstractThe thermal expansion coefficient is an important thermal parameter that influences the performance of nanodevices based on two-dimensional materials. To obtain the thermal expansion coefficient of few-layer MoS2, suspended MoS2 and supported MoS2 were systematically investigated using Raman spectroscopy in the temperature range from 77 to 557 K. The temperature-dependent evolution of the Raman frequency shift for suspended MoS2 exhibited prominent differences from that for supported MoS2, obviously demonstrating the effect due to the thermal expansion coefficient mismatch between MoS2 and the substrate. The intrinsic thermal expansion coefficients of MoS2 with different numbers of layers were calculated. Interestingly, negative thermal expansion coefficients were obtained below 175 K, which was attributed to the bending vibrations in the MoS2 layer during cooling. Our results demonstrate that Raman spectroscopy is a feasible tool for investigating the thermal properties of few-layer MoS2 and will provide useful information for its further application in photoelectronic devices.

Implications of Stress Dependency of the Thermal Expansion Coefficient on Thermal Buckling

1992 ◽  
Vol 114 (2) ◽  
pp. 189-192 ◽  
Author(s):  
C. W. Bert ◽  
C. Fu
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Temperature Dependent ◽  
Elastic Coefficient ◽  
Wide Range ◽  
Mechanics Analysis ◽  
Thermoelastic Solid ◽  
Stress Dependent ◽  
Stress Dependency

A thermosolid mechanics analysis based on sound thermodynamic and mechanical principles is derived for a thermoelastic solid in which the elastic coefficient is temperature-dependent, and thus the TEC (thermal expansion coefficient) must be stress-dependent. The theory is applied to the case of slender elastic members with full axial restraint and subjected to a uniform increase in temperature. Numerical results are presented for a wide range of materials and slenderness ratios.

Temperature-driven directional coalescence of silver nanoparticles

2016 ◽  
Vol 23 (3) ◽  
pp. 718-728 ◽  
Author(s):  
Shi Yan ◽  
Dongbai Sun ◽  
Yu Gong ◽  
Yuanyuan Tan ◽  
Xueqing Xing ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Silver Nanoparticles ◽  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Temperature Dependent ◽  
X Ray ◽  
Nanoparticle Growth

Silver nanoparticles were synthesized with a chemical reduction method in the presence of polyvinylpyrrolidone as stabilizing agent. The thermal stability behavior of the silver nanoparticles was studied in the temperature range from 25 to 700°C. Thermal gravimetric analysis was used to measure the weight loss of the silver nanoparticles. Scanning electron microscopy and high-resolution transmission electron microscopy were used to observe the morphology and the change in shape of the silver nanoparticles.In situtemperature-dependent small-angle X-ray scattering was used to detect the increase in particle size with temperature.In situtemperature-dependent X-ray diffraction was used to characterize the increase in nanocrystal size and the thermal expansion coefficient. The results demonstrate that sequential slow and fast Ostward ripening are the main methods of nanoparticle growth at lower temperatures (<500°C), whereas successive random and directional coalescences are the main methods of nanoparticle growth at higher temperatures (>500°C). A four-stage model can be used to describe the whole sintering process. The thermal expansion coefficient (2.8 × 10−5 K−1) of silver nanoparticles is about 30% larger than that of bulk silver. To our knowledge, the temperature-driven directional coalescence of silver nanocrystals is reported for the first time. Two possible mechanisms of directional coalescence have been proposed. This study is of importance not only in terms of its fundamental academic interest but also in terms of the thermal stability of silver nanoparticles.

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