Electrochemical Synthesis and Thermodynamic Properties of Pr-Ni Intermetallic Compounds in a LiCl-KCl-NiCl2 -PrCl3 Melt

2019 ◽  
Vol 6 (3) ◽  
pp. 876-884 ◽  
Author(s):  
Taiqi Yin ◽  
Yun Xue ◽  
Yongde Yan ◽  
Yanghai Zheng ◽  
Yali Song ◽  
...  
Author(s):  
Jyoti Sagar ◽  
Reetu Singh ◽  
Vijay Kumar ◽  
Sanjay Kumar ◽  
Manish P. Singh ◽  
...  

Abstract Gold-rich rare earth intermetallic compounds (viz. Ce2Au2Cd and CeAu4Cd2) show unusual magnetic and physical properties, and they have extensive applications in electronic and mechanical industries due to their good electronic and thermal behavior with high mechanical strength. In the present research article, to take full advantage of technological importance of these materials, we have investigated the structural, electronic and thermodynamic properties of Ce2Au2Cd and CeAu4Cd2 ternary intermetallic compounds using density functional theory (DFT). The electronic band structure and density of state calculations show that Ce-f orbital electrons provide metallic character to both the compounds with strong hybridization of Au-p and Cd-p orbitals at the Fermi level. The effect of temperature has been studied on the various thermodynamic parameters using the quasi-harmonic Debye model. Thermodynamic properties show that CeAu4Cd2 compound has larger mechanical resistance (or high mechanical strength or hardness) and smaller randomness compared to Ce2Au2Cd with respect to temperature.


2017 ◽  
Vol 31 (22) ◽  
pp. 1750161 ◽  
Author(s):  
Y. F. Li ◽  
S. L. Tang ◽  
Y. M. Gao ◽  
S. Q. Ma ◽  
Q. L. Zheng ◽  
...  

The mechanical and thermodynamic properties of intermetallic compounds in the Ni–Ti system are studied by first-principles calculations. All phases show anisotropic elasticity in different crystallographic directions, in which Ni3Ti and NiTi2 are approaching the isotropy structure. The elastic moduli and Vicker’s hardness of Ni–Ti system intermetallic compounds decrease in the following order: Ni3Ti [Formula: see text] B2_NiTi [Formula: see text] B19[Formula: see text]_NiTi [Formula: see text] NiTi2, and Ni3Ti shows the best mechanical properties. The intrinsic ductile nature of Ni–Ti compounds is confirmed by the obtained [Formula: see text]/[Formula: see text] ratio. The temperature dependence of linear thermal expansion coefficients (LTECs) of the compounds is estimated by the quasi-harmonic approximation (QHA) method. Ni3Ti shows the largest values among all Ni–Ti intermetallic compounds. At room temperature, the LTEC for Ni3Ti is 8.92 × 10[Formula: see text] K[Formula: see text], which falls in between the LTEC of zirconia toughened alumina (ZTA) (7.0–9.5 × 106 K[Formula: see text]) and iron matrix (9.2–16.9 × 106 K[Formula: see text]); i.e., the thermal matching of the ZTA/iron composite will be improved by introducing Ni3Ti intermetallic compound into their interface. Other thermodynamic properties such as sound velocity and Debye temperature are also obtained.


1997 ◽  
Vol 13 (08) ◽  
pp. 712-716
Author(s):  
Chen Feng ◽  
◽  
Yang Zhang-Yuan ◽  
Wen Hao ◽  
Xu Zhi-Hao

Author(s):  
Dalsung Yoon ◽  
Supathorn Phongikaroon

Thermodynamic properties of Ce-Cd intermetallic compound were investigated in LiCl-KCl-CeCl3-CdCl2 molten salt system at various temperatures. Six Ce-Cd intermetallic compounds, CeCd, CeCd2, CeCd3, Ce13Cd58, CeCd6, and CeCd11 could be observed via cyclic voltammetry (CV) and the relative Gibbs free energies for the intermetallic formations were estimated by the analysis of the anodic peaks in the CV experiments. Furthermore, an open circuit chronopotentiometry which is known as a suitable method for measuring thermodynamic values of intermetallic compounds were performed. The linear trends of the relative Gibbs free energies were found by using potential difference from CV and CP methods. It can be noted that CV method can be easy and fast tool to estimate relative Gibbs energy for intermetallic compounds of Cd-Ms (metals). For the determination of standard Gibbs free energy, enthalpy, and entropy for the intermetallic formation, CP results were used. The linear trend of the Gibbs energy were obtained against temperature changing from 698 K to 823 K. From the linear relationship, the enthalpy and entropy of the formation were calculated.


2014 ◽  
Vol 28 (03) ◽  
pp. 1450006 ◽  
Author(s):  
M. OULD KADA ◽  
T. SEDDIK ◽  
A. SAYEDE ◽  
R. KHENATA ◽  
A. BOUHEMADOU ◽  
...  

Structural, electronic, elastic and thermodynamic properties of Rh 3 X ( X = Zr , Nb , Ta ) intermetallic compounds are investigated in the framework of density functional theory (DFT). The exchange-correlation (XC) potential is treated with the generalized gradient approximation (GGA) and local density approximation (LDA). The computed ground state properties agree well with the available theoretical and experimental values. The elastic constants are obtained by calculating the total energy versus volume conserving strains using Mehl model. The electronic and bonding properties are discussed from the calculations of band structures (BSs), densities of states and electron charge densities. The volume and bulk modulus at high pressure and temperature are investigated. Additionally, thermodynamic properties such as the heat capacity, thermal expansion and Debye temperature at high pressures and temperatures are also analyzed.


2007 ◽  
Vol 316 (2) ◽  
pp. e552-e554 ◽  
Author(s):  
Jiri Pospisil ◽  
Jana Poltierova Vejpravova ◽  
Vladimir Sechovsky

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