scholarly journals Correlation study of optical, mechanical and thermal properties of BAs material and its experimental energy gap

2017 ◽  
Vol 5 (2) ◽  
pp. 79
Author(s):  
Salah Daoud
Keyword(s):  
Dielectric Constant ◽  
Thermal Properties ◽  
Bulk Modulus ◽  
Debye Temperature ◽  
Melting Temperature ◽  
Energy Gap ◽  
Theoretical Data ◽  
Index Of Refraction ◽  
Mechanical And Thermal Properties ◽  
Electronic Polarizability

The object of this work is to study the correction between the optical, mechanical and thermal properties of boron arsenide (BAs) material and its experimental optical energy gap. The index of refraction, the high-frequency dielectric constant, the optical electronegativity, the bulk modulus, the micro-hardness, the plasmon energy, the Debye temperature, the melting temperature and the electronic polarizability of BAs were estimated from its energy gap. The results obtained are analyzed in comparison with available experimental and other theoretical data. My obtained results of the reflective index and the dielectric constant agree well with other theoretical data; whereas the bulk modulus, the microhardness, the Debye temperature, and the melting temperature are slightly lower than the experimental and other theoretical data. The electronic polarizability is slightly different than other theoretical ones from the literature.

Pressure Induced Properties of UXLa1-XS Compound

2016 ◽  
Vol 28 ◽  
pp. 108-114
Author(s):  
Ashok K. Ahirwar ◽  
Mahendra Aynyas ◽  
Sankar P. Sanyal
Keyword(s):  
Experimental Data ◽  
Phase Transition ◽  
Thermal Properties ◽  
Bulk Modulus ◽  
Debye Temperature ◽  
Elastic Constants ◽  
Volume Change ◽  
Mechanical And Thermal Properties ◽  
Phase Transition Pressure ◽  
Crystal Structural

The crystal structural, mechanical and thermal properties of UXLa1-XS compound with different concentrations (x= 0.00, 0.08 and 0.40) are investigated using modified inter-ionic potential theory (MIPT), which parametrically includes the effect of coulomb screening by the delocalized f-electrons. Our calculated values of phase transition pressure, bulk modulus and volume change are agree well with the theoretical and experimental data. We have also calculated the second order elastic constants and Debye temperature of these three concentrations.

Novel soluble polyimides containing pyridine and fluorinated units: preparation, characterization, and optical and dielectric properties

RSC Advances ◽  
2016 ◽  
Vol 6 (26) ◽  
pp. 21662-21671 ◽  
Author(s):  
Weibing Dong ◽  
Yue Guan ◽  
Dejing Shang
Keyword(s):  
Dielectric Constant ◽  
Thermal Properties ◽  
Dielectric Properties ◽  
Low Dielectric Constant ◽  
Mechanical And Thermal Properties ◽  
Polyimide Films ◽  
Low Dielectric

To acquire low dielectric constant polyimide films with good mechanical and thermal properties and low CTE applied in microelectronic fields, three novel polyimides containing pyridine and –C(CF3)2– groups were firstly designed and synthesized.

scholarly journals Thermal properties of cubic zincblende thallium-phosphide from quasi-harmonic Debye model approximation

2017 ◽  
Vol 5 (1) ◽  
pp. 14 ◽  
Author(s):  
Salah Daoud
Keyword(s):  
High Pressure ◽  
Thermal Properties ◽  
Bulk Modulus ◽  
Unit Cell Volume ◽  
Theoretical Data ◽  
Debye Model ◽  
Zero Temperature ◽  
Isothermal Bulk Modulus ◽  
Model Approximation ◽  
First Order

The thermal properties of cubic zincblende (B3) thallium - phosphide (TlP) compound under high pressure up to 12 GPa have been studied using the quasi-harmonic Debye model approximation. The relative unit cell volume, the isothermal bulk modulus, the first order derivative isothermal bulk modulus, the Debye temperature and the Grüneisen parameter are studied at zero-temperature and at standard ambient temperature (298 K) respectively. Our obtained values of the different previous quantities are in general in agreement compared to other theoretical data of the literature.

scholarly journals Preparation and properties of a novel graphene fluoroxide/polyimide nanocomposite film with a low dielectric constant

RSC Advances ◽  
2017 ◽  
Vol 7 (4) ◽  
pp. 1956-1965 ◽  
Author(s):  
Xiao Chen ◽  
Haohao Huang ◽  
Xia Shu ◽  
Shumei Liu ◽  
Jianqing Zhao
Keyword(s):  
Dielectric Constant ◽  
Thermal Properties ◽  
Nanocomposite Film ◽  
Low Dielectric Constant ◽  
Mechanical And Thermal Properties ◽  
Low Dielectric ◽  
Polyimide Nanocomposite

A novel graphene fluoroxide/polyimide nanocomposite film with a low dielectric constant is prepared with excellent mechanical and thermal properties.

Low-Dielectric Constant Nanoporous Epoxy for Electronic Packaging

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Jisu Jiang ◽  
Landon Keller ◽  
Paul A. Kohl
Keyword(s):  
Dielectric Constant ◽  
Thermal Properties ◽  
Maleic Anhydride ◽  
Coefficient Of Thermal Expansion ◽  
Tangent Loss ◽  
Mechanical And Thermal Properties ◽  
Low Dielectric ◽  
Resin Formulation ◽  
Styrene Maleic Anhydride ◽  
Poly Propylene

Abstract Epoxide functionalized poly(propylene carbonate) (ePPC) was included in an epoxy resin formulation and thermally decomposed to create nanoporous epoxy film. The dielectric constant of the porous epoxy was lower than the epoxy formulation control. The introduction of 30% porosity in the epoxy lowered the dielectric constant from 3.78 to 2.76. A postporosity chemical treatment further lowered the dielectric constant. Hexamethyldisilazane (HMDS) was used to terminate the pore walls with the hydrophobic silane layer and reduce both the dielectric constant and tangent loss of the porous epoxy. Two different styrene maleic anhydride crosslinking agents were used in the epoxy formulation, styrene maleic anhydride 2000 (SMA2000) and styrene maleic anhydride 4000 (SMA4000). The effect of the maleic anhydride concentration within SMA on the electrical, mechanical, and thermal properties of porous epoxy film was evaluated. Epoxy films crosslinked with SMA2000 resulted in films with a higher dielectric constant compared to films prepared with SMA4000 due to higher mole fraction of maleic anhydride within SMA2000. However, SMA2000 crosslinked films yielded films with better mechanical and thermal properties. SMA2000 crosslinked films with 30% porosity had a coefficient of thermal expansion (CTE) of 35.2 ppm/K and glass transition temperature of 143 °C.

Structural, mechanical and thermal properties of Cu2ZnSiS4 with four structures from the first-principle calculations

2019 ◽  
Vol 33 (09) ◽  
pp. 1950067
Author(s):  
Yanli Gao ◽  
Yujing Dong
Keyword(s):  
Thermal Properties ◽  
Bulk Modulus ◽  
Elastic Constants ◽  
Density Functional ◽  
Debye Model ◽  
Energy Calculation ◽  
Mechanical And Thermal Properties ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Total Energy Calculation

In this paper, the structural, mechanical and thermal properties of the four structures of Cu2ZnSiS4 were studied on the basis of density functional theory (DFT). The generalized gradient approximation (GGA) of Perdew–Burke–Ernzerhof (PBE) was used to treat the exchange related energy and potential of total energy calculation. The independent elastic constants of the four structures are calculated, which prove that they are mechanically stable. The bulk modulus, Poisson’s ratios and universal anisotropy indices of Cu2ZnSiS4 can be calculated from the obtained elastic constants. In addition, the variation of the bulk modulus with the pressure (0–25 GPa) and temperature (0–700 K) have been reported. In order to further study the compound, the thermal properties of the compound were analyzed by using the quasi-harmonic Debye model, including specific heat, thermal expansion coefficient and Debye temperature.

Chromium effects on the microstructural, mechanical and thermal properties of a rapidly solidified eutectic Sn-Ag alloy

2019 ◽  
Vol 32 (3) ◽  
pp. 137-145 ◽  
Author(s):  
Sanaa Razzaq Abbas ◽  
Mohammed S. Gumaan ◽  
Rizk Mostafa Shalaby
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Young’S Modulus ◽  
Melting Temperature ◽  
Vickers Hardness ◽  
Lattice Distortion ◽  
Mechanical And Thermal Properties ◽  
Content Type ◽  
Melt Spun ◽  
Rapidly Solidified

Purpose This study aims to investigate the chromium (Cr) effects on the microstructural, mechanical and thermal properties of melt-spun Sn-3.5Ag alloy. Design/methodology/approach Ternary melt-spun Sn-Ag-Cr alloys were investigated using X-ray diffractions, scanning electron microscope, dynamic resonance technique, instron machine, Vickers hardness tester and differential scanning calorimetry. Findings The results revealed that the Ag3Sn intermetallic compound (IMC) and ß-Sn have been refined because of the hard inclusions’ (Cr atoms) effects, causing lattice distortion increasing these alloys. The tensile results of Sn96.4-Ag3.5-Cr0.1 alloy showed an improvement in Young’s modulus more than 100 per cent (42.16 GPa), ultimate tensile strength (UTS) by 9.4 per cent (23.9 MPa), compared with the eutectic Sn-Ag alloy due to the high concentration of Ag3Sn and their uniform distribution. Shortage in the internal friction (Q−1) of about 54 per cent (45.1) and increase in Vickers hardness of about 7.4 per cent (142.1 MPa) were also noted. Hexagonal Ag3Sn formation led to low toughness values compared to the eutectic Sn-Ag alloy, which may have resulted from the mismatching among hexagonal Ag3Sn phase with orthorhombic Ag3Sn and ß-Sn phases. Mechanically, the values of Young’s modulus have been increased, with increasing chromium content, whereas the UTS and toughness values have been decreased. The opposite of this trend appeared in Sn95.8-Ag3.5-Cr0.7 alloy, which may have been due to high lattice distortion (ƹ = 16.5 × 10−4) compared to the other alloys. Increase in the melting temperature Tm, ΔH, Cp and ΔT was because of Ag3Sn IMC formation. The low toughness of Sn96-Ag3.5-Cr0.5 and Sn95.8-Ag3.5-Cr0.7 (109.56 J/m3 and 35.66 J/m3), relatively high melting temperature Tm (223.22°C and 222.65°C) and low thermal conductivity and thermal diffusivity (32.651 w.m−1.k−1 and 0.314 m2/s) make them undesirable in the soldering process. The high UTS, high E, high thermal conductivity and diffusivity, low creep rate and low electrical resistivity, which have occurred with “0.1 Wt.%” of Cr, make this alloy desirable and reliable for soldering applications and electronic assembly. Originality/value This study provides chromium effects on the structure of the eutectic Sn-Ag rapidly solidified by melt-spinning technique. In this paper, the authors compared the elastic modulus of the melt-spun compositions, which have been resulted from the Static method with that have been resulted from the Dynamic method. This paper presents new improvements in mechanical and thermal performance.

scholarly journals Polypropylene/Graphene Nanocomposites: Effects of GNP Loading and Compatibilizers on the Mechanical and Thermal Properties

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3924 ◽  
Author(s):  
Mohammad A. Al-Saleh ◽  
Abdirahman A. Yussuf ◽  
Salah Al-Enezi ◽  
Roaya Kazemi ◽  
Mat Uzir Wahit ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Thermal Properties ◽  
Maleic Anhydride ◽  
Melting Temperature ◽  
Significant Influence ◽  
Research Work ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry

In this research work, graphene nanoplatelets (GNP) were selected as alternative reinforcing nanofillers to enhance the properties of polypropylene (PP) using different compatibilizers called polypropylene grafted maleic anhydride (PP-g-MA) and ethylene-octene elastomer grafted maleic anhydride (POE-g-MA). A twin screw extruder was used to compound PP, GNP, and either the PP-g-MA or POE-g-MA compatibilizer. The effect of GNP loading on mechanical and thermal properties of neat PP was investigated. Furthermore, the influence and performance of different compatibilizers on the final properties, such as mechanical and thermal, were discussed and reported. Tensile, flexural, impact, melting temperature, crystallization temperature, and thermal stability were evaluated by using a universal testing system, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). For mechanical properties, it was found that increasing GNP content from 1 wt.% to 5 wt.% increased tensile strength of the neat PP up to 4 MPa. The influence of compatibilizers on the mechanical properties had been discussed and reported. For instance, the addition of PP-g-MA compatibilizer improved tensile strength of neat PP with GNP loading. However, the addition of compatibilizer POE-g-MA slightly decreased the tensile strength of neat PP. A similar trend of behavior was observed for flexural strength. For thermal properties, it was found that both GNP loading and compatibilizers have no significant influence on both crystallization and melting temperature of neat PP. For thermal stability, however, it was found that increasing the GNP loading had a significant influence on improving the thermal behavior of neat PP. Furthermore, the addition of compatibilizers into the PP/GNP nanocomposite had slightly improved the thermal stability of neat PP.

Thermal Properties and Transition Temperatures of AlB2-Type Diborides

2015 ◽  
Vol 817 ◽  
pp. 740-747
Author(s):  
Ming Jun Peng ◽  
Yong Hua Duan ◽  
Yong Sun
Keyword(s):  
Thermal Properties ◽  
Bulk Modulus ◽  
Melting Temperature ◽  
First Principles ◽  
Transition Temperatures ◽  
Coupling Constant ◽  
Phonon Coupling ◽  
Electron Phonon Coupling ◽  
The Relationship ◽  
Theoretical Results

The thermal properties, cohesion and transition temperatures of 14 compounds in the AlB2-type diborides have been calculated by first-principles. The obtained thermal properties, cohesion and transition temperatures Tc were compared with both available experimental data and other theoretical results. The relationship among enthalpy formation, bulk modulus and melting temperature in these diborides were further analyzed. The results illustrate that ZrB2 is the most stable, and AuB2 has the largest c/a ratio and it is also most unstable to a phase separation. It is observed that the diborides including Mg, Sc, and Hf series with a more negative enthalpy of formation have a larger bulk modulus and higher melting temperature. AuB2 has higher electron-phonon coupling constant and hence possesses a higher Tc.

Effect of Sc, Y, Yb, Hf, Ce on Mechanical and Thermal Properties of La2Zr2O7: First-Principles Calculations

2015 ◽  
Vol 1120-1121 ◽  
pp. 85-93 ◽  
Author(s):  
Lei Jin ◽  
Pei Zhong Li ◽  
Chun Zhu Jiang ◽  
Guo Dong Zhou ◽  
Hai Bin Zhou ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Sound Velocity ◽  
Young’S Modulus ◽  
Debye Temperature ◽  
Elastic Constants ◽  
First Principles ◽  
Young's Modulus ◽  
Elastic Stiffness ◽  
Mechanical And Thermal Properties

In order to achieve better understanding of the effect of dopant (Sc, Y, Yb, Hf and Ce) on elastic stiffness and thermal properties of La2Zr2O7. The related calculations were performed using the first principles methods. The predicted elastic constants indicate that La2Zr2O7 and oxidations-La2Zr2O7 (oxidations refer to Sc2O3, Y2O3, Yb2O3, HfO2 and CeO2) are mechanically stable structures. And then the numerical estimates of bulk modulus, shear modulus, Young’s modulus were performed using the calculated elastic constants. After these mechanical properties are obtained, sound velocity, Debye temperature and theoretical minimum thermal conductivity of La2Zr2O7 and oxidations-La2Zr2O7 are calculated and analyzed in detail. The available experimental results and our calculations are basically satisfactory. The calculated results indicate that Young’s modulus, mean sound velocity, Debye temperature and minimum thermal conductivity of La2Zr2O7 can be decreased by dopants. CeO2 has extraordinary ability to decrease thermal conductivity in these dopant oxidations.

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