First principles calculation of intermetallic compounds in FeTiCoNiVCrMnCuAl system high entropy alloy

Fast electron irradiation can induce the solid-state amorphization (SSA) of many intermetallic compounds. The occurrence of SSA stimulated by fast electron irradiation was found in the Al0.5TiZrPdCuNi high-entropy alloy (HEA). The relationship between the occurrence of SSA in intermetallic compounds under fast electron irradiation and the empirical alloy parameters for predicting the solid-solution-formation tendency in HEAs was discussed. The occurrence of SSA in intermetallic compounds was hardly predicted, only by the alloy parameters of δ or ΔHmix, which have been widely used for predicting solid-solution formation in HEAs. All intermetallic compounds with ΔHmix ≤ -35 kJ/mol and those with δ ≥ 12.5 exhibit the occurrence of SSA. This implies that the intermetallic compounds with a largely negative ΔHmix value and a largely positive δ parameter are favorable for the occurrence of SSA.

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Diffusion Barrier Performance of AlCrTaTiZr/AlCrTaTiZr-N High-Entropy Alloy Films for Cu/Si Connect System

Entropy ◽

10.3390/e22020234 ◽

2020 ◽

Vol 22 (2) ◽

pp. 234

Author(s):

Chunxia Jiang ◽

Rongbin Li ◽

Xin Wang ◽

Hailong Shang ◽

Yong Zhang ◽

...

Keyword(s):

Intermetallic Compounds ◽

Diffusion Barrier ◽

Lattice Mismatch ◽

Copper Film ◽

Amorphous Structure ◽

High Entropy Alloy ◽

Alloy Films ◽

High Entropy ◽

Atom Diffusion ◽

Barrier Performance

In this study, high-entropy alloy films, namely, AlCrTaTiZr/AlCrTaTiZr-N, were deposited on the n-type (100) silicon substrate. Then, a copper film was deposited on the high-entropy alloy films. The diffusion barrier performance of AlCrTaTiZr/AlCrTaTiZr-N for Cu/Si connect system was investigated after thermal annealing for an hour at 600 °C, 700 °C, 800 °C, and 900 °C. There were no Cu-Si intermetallic compounds generated in the Cu/AlCrTaTiZr/AlCrTaTiZr-N/Si film stacks after annealing even at 900 °C through transmission electron microscopy (TEM) and atomic probe tomography (APT) analysis. The results indicated that AlCrTaTiZr/AlCrTaTiZr-N alloy films can prevent copper diffusion at 900 °C. The reason was investigated in this work. The amorphous structure of the AlCrTaTiZr layer has lower driving force to form intermetallic compounds; the lattice mismatch between the AlCrTaTiZr and AlCrTaTiZ-rN layers increased the diffusion distance of the Cu atoms and the difficulty of the Cu atom diffusion to the Si substrate.

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First-Principles Design of Refractory High Entropy Alloy VMoNbTaW

Entropy ◽

10.3390/e20120965 ◽

2018 ◽

Vol 20 (12) ◽

pp. 965 ◽

Cited By ~ 4

Author(s):

Shumin Zheng ◽

Shaoqing Wang

Keyword(s):

Elastic Properties ◽

First Principles ◽

High Entropy Alloy ◽

Low Density ◽

High Entropy ◽

System A ◽

Small Influence ◽

High Concentrations ◽

General Guidance ◽

Selection Of

The elastic properties of seventy different compositions were calculated to optimize the composition of a V–Mo–Nb–Ta–W system. A new model called maximum entropy approach (MaxEnt) was adopted. The influence of each element was discussed. Molybdenum (Mo) and tungsten (W) are key elements for the maintenance of elastic properties. The V–Mo–Nb–Ta–W system has relatively high values of C44, bulk modulus (B), shear modulus (G), and Young’s modulus (E), with high concentrations of Mo + W. Element W is brittle and has high density. Thus, low-density Mo can substitute part of W. Vanadium (V) has low density and plays an important role in decreasing the brittleness of the V–Mo–Nb–Ta–W system. Niobium (Nb) and tantalum (Ta) have relatively small influence on elastic properties. Furthermore, the calculated results can be used as a general guidance for the selection of a V–Mo–Nb–Ta–W system.

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An investigation of high entropy alloy conductivity using first-principles calculations

Applied Physics Letters ◽

10.1063/5.0065239 ◽

2021 ◽

Vol 119 (12) ◽

pp. 121903

Author(s):

Vishnu Raghuraman ◽

Yang Wang ◽

Michael Widom

Keyword(s):

First Principles ◽

High Entropy Alloy ◽

First Principles Calculations ◽

High Entropy

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Structural and Thermodynamic Properties of the High-Entropy Alloy AlCoCrFeNi Based on First-Principles Calculations

Frontiers in Materials ◽

10.3389/fmats.2020.590143 ◽

2020 ◽

Vol 7 ◽

Author(s):

Juefei Wu ◽

Zhen Yang ◽

Jiawei Xian ◽

Xingyu Gao ◽

Deye Lin ◽

...

Keyword(s):

Thermodynamic Properties ◽

First Principles ◽

High Pressures ◽

Dynamic Properties ◽

Field Potential ◽

The Body ◽

High Entropy Alloy ◽

High Entropy Alloys ◽

Local Lattice Distortion ◽

High Entropy

During the past two decades, the high-entropy alloy AlCoCrFeNi has attracted much attention due to its outstanding thermal and mechanical properties under ambient conditions. However, the exploration on the thermodynamic properties of this alloy under high temperatures and high pressures is relatively insufficient. Combining structural modeling with the similar atomic environment (SAE) method and first-principles simulations with the modified mean-field potential (MMFP) approach, we studied the lattice and magnetic structure as well as the thermodynamic properties of the body-centered-cubic AlCoCrFeNi, through supercell simulations. AlCoCrFeNi was found to display a strong local lattice distortion compared with typical 3d high-entropy alloys; the ferromagnetic structure stable at 0 K was predicted to transform to the paramagnetic structure at the Curie temperature TC = 279.75 K, in good agreement with previous calculations; the calculated equilibrium volumes, bulk modulus, and shock Hugoniot all agree well with available experimental data and other theoretical values. These results demonstrate the validity and reliability of our methods used to study the dynamic properties of AlCoCrFeNi, providing a promising scheme for accessing the dynamic properties of sophisticated high-entropy alloys.

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