scholarly journals Is Configurational Entropy the Main Stabilizing Term in Rock-Salt Mg0.2Co0.2Ni0.2Cu0.2Zn0.2O High-Entropy Oxide?

2021 ◽  
Author(s):  
Martina Fracchia ◽  
Mauro Coduri ◽  
Maela Manzoli ◽  
Paolo Ghigna ◽  
Umberto Anselmi-Tamburini
Keyword(s):  
Solid Solution ◽  
Rock Salt ◽  
Single Phase ◽  
Configurational Entropy ◽  
Rock Salt Structure ◽  
High Entropy ◽  
Reversible Transformation ◽  
Salt Structure ◽  
Cubic Structure

We question the conclusions reported in the paper "Entropy-stabilized Oxides, by C. Rost et al., by looking into the role of configurational entropy as the stabilization of the rock-salt cubic structure of the Mg0.2Co0.2Ni0.2Cu0.2Zn0.2O (HEO) solid solution (SS). First, we demonstrate that configurational entropy can be reduced from 1.61R for HEO to 0.5R for a two-member SS, still obtaining a single-phase material if the molar fractions of ZnO and CuO are 0.2. These SSs behave identically as HEO regarding the reversible transformation between a multi- and single-phase states when temperatures are cycled between 800 and 1000 °C. Second, we demonstrate that the different SSs presenting a configurational entropy significantly lower than HEO, are less prone to the cubic to tetragonal structural distortion, suggesting that the configurational entropy has not the central role as stabilizing factor of the rock-salt structure.<br>

scholarly journals Is Configurational Entropy the Main Stabilizing Term in Rock-Salt Mg0.2Co0.2Ni0.2Cu0.2Zn0.2O High-Entropy Oxide?

2021 ◽  
Author(s):  
Martina Fracchia ◽  
Mauro Coduri ◽  
Maela Manzoli ◽  
Paolo Ghigna ◽  
Umberto Anselmi-Tamburini
Keyword(s):  
Solid Solution ◽  
Rock Salt ◽  
Single Phase ◽  
Configurational Entropy ◽  
Rock Salt Structure ◽  
High Entropy ◽  
Reversible Transformation ◽  
Salt Structure ◽  
Cubic Structure

We question the conclusions reported in the paper "Entropy-stabilized Oxides, by C. Rost et al., by looking into the role of configurational entropy as the stabilization of the rock-salt cubic structure of the Mg0.2Co0.2Ni0.2Cu0.2Zn0.2O (HEO) solid solution (SS). First, we demonstrate that configurational entropy can be reduced from 1.61R for HEO to 0.5R for a two-member SS, still obtaining a single-phase material if the molar fractions of ZnO and CuO are 0.2. These SSs behave identically as HEO regarding the reversible transformation between a multi- and single-phase states when temperatures are cycled between 800 and 1000 °C. Second, we demonstrate that the different SSs presenting a configurational entropy significantly lower than HEO, are less prone to the cubic to tetragonal structural distortion, suggesting that the configurational entropy has not the central role as stabilizing factor of the rock-salt structure.<br>

Operando X-ray absorption investigations into the role of Fe in the electrochemical stability and oxygen evolution activity of Ni1−xFexOy nanoparticles

2018 ◽  
Vol 6 (47) ◽  
pp. 24534-24549 ◽  
Author(s):  
Daniel F. Abbott ◽  
Emiliana Fabbri ◽  
Mario Borlaf ◽  
Francesco Bozza ◽  
Robin Schäublin ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Oxygen Evolution ◽  
Rock Salt ◽  
Electrochemical Stability ◽  
Rock Salt Structure ◽  
X Ray ◽  
Structural And Electronic Properties ◽  
Salt Structure ◽  
X Ray Absorption

The structural and electronic properties of rock salt-type Ni–Fe oxides are investigated under OER conditions. The inclusion of Fe in the rock-salt structure is shown to inhibit the transformation to more layered and disordered polymorphs.

Lithium Extraction and Insertion Behavior of Nanocrystalline Li[sub 2]TiO[sub 3]-LiFeO[sub 2] Solid Solution with Cubic Rock Salt Structure

2003 ◽  
Vol 150 (5) ◽  
pp. A638 ◽  
Author(s):  
Hikari Shigemura ◽  
Mitsuharu Tabuchi ◽  
Hikari Sakaebe ◽  
Hironori Kobayashi ◽  
Hiroyuki Kageyama
Keyword(s):  
Solid Solution ◽  
Rock Salt ◽  
Rock Salt Structure ◽  
Salt Structure

scholarly journals The Young Modulus and Microhardness Anisotropy in (Pb,Cd)Te Solid Solution Crystallizing in the Rock Salt Structure and Containing 5% of Cd

2017 ◽  
Vol 132 (2) ◽  
pp. 343-346 ◽  
Author(s):  
E. Łusakowska ◽  
S. Adamiak ◽  
P. Adamski ◽  
R. Kuna ◽  
R. Minikayev ◽  
...  
Keyword(s):  
Solid Solution ◽  
Rock Salt ◽  
Young Modulus ◽  
Rock Salt Structure ◽  
Salt Structure

scholarly journals Unprecedented Al supersaturation in single-phase rock salt structure VAlN films by Al+ subplantation

2017 ◽  
Vol 121 (17) ◽  
pp. 171907 ◽  
Author(s):  
G. Greczynski ◽  
S. Mráz ◽  
M. Hans ◽  
D. Primetzhofer ◽  
J. Lu ◽  
...  
Keyword(s):  
Rock Salt ◽  
Single Phase ◽  
Rock Salt Structure ◽  
Salt Structure

Li0.625Al0.125H0.25Cl0.75O0.25 Superionic Conductor with Disordered Rock-Salt Structure

2021 ◽  
Author(s):  
Qian Zhang ◽  
William Arnold ◽  
Zachary D. Hood ◽  
Yang Li ◽  
Rachel DeWees ◽  
...  
Keyword(s):  
Rock Salt ◽  
Superionic Conductor ◽  
Rock Salt Structure ◽  
Salt Structure

A review on phase prediction in high entropy alloys

2021 ◽  
pp. 095440622110089
Author(s):  
Vinay Kumar Soni ◽  
S Sanyal ◽  
K Raja Rao ◽  
Sudip K Sinha
Keyword(s):  
Solid Solution ◽  
Phase Formation ◽  
Single Phase ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
Modeling Tools ◽  
High Entropy ◽  
Recent Developments ◽  
Phase Prediction ◽  
The Stability

The formation of single phase solid solution in High Entropy Alloys (HEAs) is essential for the properties of the alloys therefore, numerous approach were proposed by many researchers to predict the stability of single phase solid solution in High Entropy Alloy. The present review examines some of the recent developments while using computational intelligence techniques such as parametric approach, CALPHAD, Machine Learning etc. for prediction of various phase formation in multicomponent high entropy alloys. A detail study of this data-driven approaches pertaining to the understanding of structural and phase formation behaviour of a new class of compositionally complex alloys is done in the present investigation. The advantages and drawbacks of the various computational are also discussed. Finally, this review aims at understanding several computational modeling tools complying the thermodynamic criteria for phase formation of novel HEAs which could possibly deliver superior mechanical properties keeping an aim at advanced engineering applications.

scholarly journals Al, Cu and Zr Addition to High Entropy Alloys: The Effect on Recrystallization Temperature

2018 ◽  
Vol 941 ◽  
pp. 1137-1142
Author(s):  
Elena Colombini ◽  
Andrea Garzoni ◽  
Roberto Giovanardi ◽  
Paolo Veronesi ◽  
Angelo Casagrande
Keyword(s):  
Solid Solution ◽  
Grain Size ◽  
Single Phase ◽  
Boundary Energy ◽  
Cold Deformation ◽  
Recrystallization Temperature ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Ni Alloy ◽  
Sluggish Diffusion

The equimolar Cr, Mn, Fe, Co and Ni alloy, first produced in 2004, was unexpectedly found to be single-phase. Consequently, a new concept of materials was developed: high entropy alloys (HEA) forming a single solid-solution with a near equiatomic composition of the constituting elements. In this study, an equimolar CoCrFeMnNi HEA was modified by the addition of 5 at% of either Al, Cu or Zr. The cold-rolled alloys were annealed for 30 minutes at high temperature to investigate the recrystallization kinetics. The evolution of the grain boundary and the grain size were investigated, from the as-cast to the recrystallized state. Results show that the recrystallized single phase FCC structures exhibits different twin grains density, grain size and recrystallization temperatures as a function of the at.% of modifier alloying elements added. In comparison to the equimolar CoCrFeMnNi, the addition of modifier elements increases significantly the recrystallization temperature after cold deformation. The sluggish diffusion (typical of HEA alloys), the presence of a solute in solid solution as well as the low twin boundary energy are responsible for the lower driving force for recrystallization.

Sign in / Sign up

Export Citation Format

Share Document