Novel rare-earth and transition metal-based entropy stabilized oxides with spinel structure

Parida, Tripta; Karati, Anirudha; Guruvidyathri, K.; Murty, B.S.; Markandeyulu, G.

doi:10.1016/j.scriptamat.2019.12.027

Cited by 51 publications

(15 citation statements)

References 25 publications

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“…The model was also designed for solid solutions, however, it is based on pairwise geometric comparisons of adjacent atoms, so we adapted the model to only compare the metals with anions in the structure. A limitation of this model is its inability to describe the more complex crystal structures that exist in high-entropy ceramics, including perovskite oxides 14 and spinels 60 . The root mean squared residual strain calculated with this model correlates extremely well with the calculated configurational entropy values (Pearson correlation coefficient = 0.95, see Supplementary Fig.…”

Section: Resultsmentioning

confidence: 99%

Bulk high-entropy nitrides and carbonitrides

Dippo

Mesgarzadeh

Harrington

et al. 2020

Sci Rep

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High-entropy ceramics have potential to improve the mechanical properties and high-temperature stability over traditional ceramics, and high entropy nitrides and carbonitrides (HENs and HECNs) are particularly attractive for high temperature and high hardness applications. The synthesis of 5 bulk HENs and 4 bulk HECNs forming single-phase materials is reported herein among 11 samples prepared. The hardness of HENs and HECNs increased by an average of 22% and 39%, respectively, over the rule-of-mixtures average of their monocarbide and mononitride precursors. Similarly, elastic modulus values increased by an average of 17% in nitrides and 31% in carbonitrides over their rule-of-mixtures values. The enhancement in mechanical properties is tied to an increase in the configurational entropy and a decrease in the valence electron concentration, providing parameters for tuning mechanical properties of high-entropy ceramics.

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Section: Resultsmentioning

confidence: 99%

Bulk high-entropy nitrides and carbonitrides

Dippo

Mesgarzadeh

Harrington

et al. 2020

Sci Rep

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“…Inspired by the pioneering work of Rost et al [29], most of the researches focus on the synthesis and property exploring of entropy stabilized oxides. Shortly, oxides with rock salt [21,29,[63][64][65][66][67], fluorite [38,60,[68][69][70][71], pyrochlore [36,37,[72][73][74][75], and spinel [80][81][82][83] structures were explored and fascinating properties brought by high-entropy effects have been reported. Gild et al [34] extended the material systems to ultrahigh temperature ceramics (UHTCs) by fabricating high-entropy borides with AlB 2 structure.…”

Section: Electronic Structure and Band Gap Engineeringmentioning

confidence: 99%

High-entropy ceramics: Present status, challenges, and a look forward

et al. 2021

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High-entropy ceramics (HECs) are solid solutions of inorganic compounds with one or more Wyckoff sites shared by equal or near-equal atomic ratios of multi-principal elements. Although in the infant stage, the emerging of this new family of materials has brought new opportunities for material design and property tailoring. Distinct from metals, the diversity in crystal structure and electronic structure of ceramics provides huge space for properties tuning through band structure engineering and phonon engineering. Aside from strengthening, hardening, and low thermal conductivity that have already been found in high-entropy alloys, new properties like colossal dielectric constant, super ionic conductivity, severe anisotropic thermal expansion coefficient, strong electromagnetic wave absorption, etc., have been discovered in HECs. As a response to the rapid development in this nascent field, this article gives a comprehensive review on the structure features, theoretical methods for stability and property prediction, processing routes, novel properties, and prospective applications of HECs. The challenges on processing, characterization, and property predictions are also emphasized. Finally, future directions for new material exploration, novel processing, fundamental understanding, in-depth characterization, and database assessments are given.

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“…HEO materials have ample structural diversity with exciting properties, which form a promising novel class of materials for a broad range of applications such as structural to functional materials. For instance, a recent study by Banerjee et al [28] showed that HEOs can be a potential candidate for thermoelectric materials for energy harvesting as these materials exhibited ultralow thermal conductivities at different temperature ranges. A study by Edalati et al [29] on the photocatalytic properties of HEOs for hydrogen evolution, on the other hand, showed an appreciable light absorbance in the visible-light region for water splitting.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterizations of (Mg, Co, Ni, Cu, Zn)O high-entropy oxides

et al. 2021

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High-temperature structural ceramic materials require stability in terms of thermal and mechanical properties. High entropy oxides (HEOs) are among the emerging novel family of advanced ceramic materials with peculiar functional properties. However, their thermal stabilities and mechanical properties are not well investigated. In this work, HEO systems were synthesized from binary oxides of MgO, CoO, NiO, CuO, and ZnO using solid-state reaction method at high temperature, after obtaining the individual oxides through co-precipitation methods. The phase purity of as-synthesized and sintered samples was characterized using X-ray powder diffraction, while the microstructural investigation was performed using Scanning electron microscopy. Mechanical property of the sintered samples at different sintering times and temperatures was investigated and the sample sintered at a sintering temperature of 1200 °C for 15 h sintering time showed a maximum Vickers hardness of about 16 GPa. This result is comparable with some of the hard ceramic materials, and therefore the materials could be a potential candidate for structural applications.

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Novel rare-earth and transition metal-based entropy stabilized oxides with spinel structure

Cited by 51 publications

References 25 publications

Bulk high-entropy nitrides and carbonitrides

Bulk high-entropy nitrides and carbonitrides

High-entropy ceramics: Present status, challenges, and a look forward

Synthesis and characterizations of (Mg, Co, Ni, Cu, Zn)O high-entropy oxides

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