scholarly journals The Thermal Properties of L12 Phases in Aluminum Enhanced by Alloying Elements

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1420
Author(s):  
Jihang Lan ◽  
Zhaoqun Chen ◽  
Linghong Liu ◽  
Qingzhou Zhang ◽  
Mengdong He ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Density Functional ◽  
High Strength ◽  
Careful Analysis ◽  
Al Alloys ◽  
Functional Theory ◽  
Covalently Bonded ◽  
The Density Functional Theory ◽  
Firm Basis ◽  
Thermal Stability Of

The L12 type trialuminide compounds Al3M possess outstanding mechanical properties, which enable them to be ideal for dispersed strengthening phases for the high-strength thermally stable Al based alloys. Ab-initio calculations based on the density functional theory (DFT) were performed to study the structural, electronic, thermal, and thermodynamic properties of L12-Al3M (M = Er, Hf, Lu, Sc, Ti, Tm, Yb, Li, Mg, Zr) structures in Al alloys. The total energy calculations showed that the L12 structures are quite stable. On the basis of the thermodynamic calculation, we found that the Yb, Lu, Er, and Tm atoms with a larger atomic radii than Al promoted the thermal stability of the Al alloys, and the thermal stability rank has been constructed as: Al3Yb > Al3Lu > Al3Er > Al3Tm > Al, which shows an apparent positive correlation between the atomic size and thermal stability. The chemical bond offers a firm basis upon which to forge links not only within chemistry but also with the macroscopic properties of materials. A careful analysis of the charge density indicated that Yb, Lu, Er, and Tm atoms covalently bonded to Al, providing a strong intrinsic basis for the thermal stability of the respective structures, suggesting that the addition of big atoms (Yb, Lu, Er, and Tm) are beneficial for the thermal stability of Al alloys.

DFT study on thermo-elastic properties of Ru2FeZ (Z = Si, Ge, Sn) Heusler alloys

2018 ◽  
Vol 32 (05) ◽  
pp. 1850045 ◽  
Author(s):  
Aneeza Iftikhar ◽  
Afaq Ahmad ◽  
Iftikhar Ahmad ◽  
Muhammad Rizwan
Keyword(s):  
Thermal Stability ◽  
Elastic Properties ◽  
Density Functional ◽  
Heusler Alloys ◽  
Longitudinal Mode ◽  
Transverse Mode ◽  
Functional Theory ◽  
Formation Energies ◽  
Thermal Stability Of ◽  
Temperature Melting

We studied the thermo-elastic properties of Ru2FeZ (Z[Formula: see text]=[Formula: see text]Si, Ge, Sn) Heusler alloys within the framework of density functional theory. Thermo-elastic properties corresponding to elastic modulus, anisotropy, phase stability, elastic wave velocities, thermal stability, Debye temperature, melting temperature, thermal conductivity and formation energy are calculated. The elastic constants C[Formula: see text] predict the structural and dynamical stabilities while the formation energies show thermal stability of the alloys at 0 K. Pugh’s and Poisson’s ratios display the ductile nature of alloys. All alloys are anisotropic and we also observed that Ru2FeSn is the hardest material than Ru2FeSi and Ru2FeGe. Moreover, longitudinal mode of vibrations are also observed and are maximum along [100], [110] and [111] directions than the transverse mode of vibrations.

scholarly journals Controlling Thermal Stability and Volatility of Organogold(I) Compounds for Vapor Deposition with Complementary Ligand Design

2019 ◽  
Author(s):  
Matthew Griffiths ◽  
Zachary Dubrawski ◽  
Goran Bačić ◽  
Jason Masuda ◽  
Achini Japahuge ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Vapor Deposition ◽  
Figure Of Merit ◽  
Density Functional ◽  
Computational Techniques ◽  
Functional Theory ◽  
Design Studies ◽  
X Ray Crystallography ◽  
Compare And Contrast ◽  
Thermal Stability Of

We compare and contrast the volatility and thermal stability of a family of twelve organometallic gold(I) compounds using a combination of X-ray crystallography, thermogravimetric analysis (TGA), and density functional theory (DFT) techniques. Pentafluorophenyl is used as a new ligand for vapor deposition which produces rather low volatility, but very thermally stable compounds when combined with PMe<sub>3</sub> and <i>N</i>,<i>N</i>'-di-<i>tert</i>-butylimidazolidin-2-ylidene. We introduce a precursor figure of merit that can be used to rank precursor usefulness. Using DFT, we find a linear correlation between Au-L bond strength and thermal stability, which demonstrates the power of computational techniques to predict successful synthetic targets for future precursor design studies.

scholarly journals Controlling Thermal Stability and Volatility of Organogold(I) Compounds for Vapor Deposition with Complementary Ligand Design

2019 ◽  
Author(s):  
Matthew Griffiths ◽  
Zachary Dubrawski ◽  
Goran Bačić ◽  
Jason Masuda ◽  
Achini Japahuge ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Vapor Deposition ◽  
Figure Of Merit ◽  
Density Functional ◽  
Computational Techniques ◽  
Functional Theory ◽  
Design Studies ◽  
X Ray Crystallography ◽  
Compare And Contrast ◽  
Thermal Stability Of

We compare and contrast the volatility and thermal stability of a family of twelve organometallic gold(I) compounds using a combination of X-ray crystallography, thermogravimetric analysis (TGA), and density functional theory (DFT) techniques. Pentafluorophenyl is used as a new ligand for vapor deposition which produces rather low volatility, but very thermally stable compounds when combined with PMe<sub>3</sub> and <i>N</i>,<i>N</i>'-di-<i>tert</i>-butylimidazolidin-2-ylidene. We introduce a precursor figure of merit that can be used to rank precursor usefulness. Using DFT, we find a linear correlation between Au-L bond strength and thermal stability, which demonstrates the power of computational techniques to predict successful synthetic targets for future precursor design studies.

scholarly journals Spectroscopic Insight into Tetrahedrally Distorted Square Planar Copper(II) Complex: XRD/HSA, Physicochemical, DFT, and Thermal Investigations

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1179
Author(s):  
Ahmed Boshaala ◽  
Abrahem F. Abrahem ◽  
Abdulla Ali Almughery ◽  
Nabil Al-Zaqri ◽  
Abdelkader Zarrouk ◽  
...  
Keyword(s):  
Density Functional ◽  
Gravimetric Analysis ◽  
Perfect Agreement ◽  
Functional Theory ◽  
Square Planar ◽  
The Density Functional Theory ◽  
Thermal Investigations ◽  
Ligand Coordination ◽  
Thermal Stability Of ◽  
Cis Isomer

The reaction of bidentate N-S-thione-Schiff base, (E)-benzyl 2-(1-(4-chlorophenyl)- ethylidene)hydrazinecarbodithioate, with Cu(NO3)2·3H2O produced a cis-Cu(II) complex. The molecular structure was confirmed and characterized by CHN-EA, FAB-MS, IR, and UV-Vis analyses. The XRD supported cis-isomer of the bis anionic bidentate N (azomethine) and S (thiol) ligand coordination mode in tetrahedrally distorted square planar, rarely reported in the literature. The results of the XRD-bond lengths were in perfect agreement with the density functional theory (DFT) calculation. DFT-calculated angles around the Cu(II) center displayed slightly less distortion around the metal center from those of XRD. Additionally, the thermal stability of the complex was evaluated via thermal gravimetric analysis (TGA). Two-dimensional fingerprint (2D-FP), Hirshfeld surface analysis (HSA), and molecular electrostatic potential (MEP) support the XRD-packing results with the existence of the H⸱⸱⸱Cl and CH⸱⸱⸱π bonds as the main interactions in the crystal lattice of the desired complex.

The Structure and Stability of C20 Dimer

2015 ◽  
Vol 1096 ◽  
pp. 228-231
Author(s):  
Ting Ting Dai ◽  
Pei Ying Huo ◽  
Ji Cai Yu ◽  
Huan Liu ◽  
Yan Xia Song ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Ground State ◽  
Electronic Structures ◽  
Density Functional ◽  
Ground State Structure ◽  
State Structure ◽  
Carbon Cage ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
The Stability

The possible geometrical and electronic structures of C20dimer are optimized by using the density functional theory at B3LYP/LANL2DZ level, stable structure of C20dimer are obtained. The stability of the ground state structure have been studied. The results showed that: there was a slight expansion in carbon cage of C20 dimer ; its chemical stability and thermal stability have been improved.

Investigation of mechanical properties and thermal stability of the thinnest tungsten nanowire by density functional theory

RSC Advances ◽  
2016 ◽  
Vol 6 (2) ◽  
pp. 1158-1168 ◽  
Author(s):  
Hui-Lung Chen ◽  
Shin-Pon Ju ◽  
Ken-Huang Lin ◽  
Jia-Yun Li ◽  
Hsin-Tsung Chen
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Density Functional Theory ◽  
Simulated Annealing ◽  
Density Functional ◽  
Tight Binding ◽  
Functional Theory ◽  
Basin Hopping ◽  
Penalty Algorithm ◽  
Thermal Stability Of

The most stable structure of the thinnest tungsten (W) nanowire with the radius of 1.9 Å was predicted by the simulated annealing basin-hopping method (SABH) with the tight-binding (TB) potential and the penalty algorithm.

Trends in the thermal stability of two-dimensional covalent organic frameworks

2021 ◽  
Author(s):  
Austin M. Evans ◽  
Matthew R. Ryder ◽  
Woojung Ji ◽  
Michael J. Strauss ◽  
Amanda R. Corcos ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Density Functional ◽  
Variable Temperature ◽  
Covalent Organic Frameworks ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Diffuse Reflectance Infrared Spectroscopy ◽  
Diffuse Reflectance Infrared ◽  
Thermal Stability Of

Here, we study the thermal stability of ten 2D covalent organic frameworks using a combination of variable-temperature X-ray diffraction, thermogravimetric analysis, diffuse reflectance infrared spectroscopy, and density-functional theory.

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