High-entropy alumino-silicides: a novel class of high-entropy ceramics

Abstract

High-entropy ceramics (HECs) are gaining significant interest due to their huge composition space, unique microstructure, and adjustable properties. Previously reported studies focus mainly on HECs with the multi-cationic structure, while HECs with more than one anion are rarely studied. Herein we reported a new class of HECs, namely highentropy alumino-silicides (Mo 0.25 Nb 0.25 Ta 0.25 V 0.25)(Al 0.5 Si 0.5) 2 (HEAS-1) with multi-cationic and-anionic structure. The formation possibility of HEAS-1 was first theoretically analyzed from the aspects of thermodynamics and lattice size difference based on the first-principles calculations and then the HEAS-1 were successfully synthesized by the solid-state reaction at 1573 K. The as-synthesized HEAS-1 exhibited good single-crystal hexagonal structure of metal alumino-silicides and simultaneously possessed high compositional uniformity. This study not only enriches the categories of HECs but also will open up a new research field on HECs with multi-cationic and-anionic structure.

Thermophysical and mechanical properties of novel high‐entropy metal nitride‐carbides

“…Therefore, the exploration of HECs with multi‐cationic and ‐anionic sublattice structure is of great interest to the scientific community. Nevertheless, only few HECs with multi‐cationic and ‐anionic sublattice structure, namely high‐entropy oxyfluorides and high‐entropy alumino‐silicides, 16,17 have been developed until now and much more categories of HECs with multi‐cationic and ‐anionic sublattice structure are still needed to be developed for the scientific community.…”

Fabrication of High-Entropy Disilicide Nanopowders via Molten Salt-Assisted Magnesium Thermal Reduction

“…1,2 Compared to conventional single phase ceramics, HECs process unique properties and potential applications in many elds due to their high-entropy, severe lattice-distortion, sluggish diffusion, and cocktail effects. 3 Heretofore, numerous HECs, including oxides, 1,4 carbides, [5][6][7][8] diborides, 3,9−11 and disilicides, [12][13][14] have been extensively investigated due to their high-melting point (> 3273 K), excellent chemical stability at high temperature, and high hardness. Among these HECs, high-entropy disilicides are considered as the most promising high-temperature candidate material in that their individual components possess high melting points, high-temperature mechanical property retention, and excellent oxidation resistance.…”

“…Among these HECs, high-entropy disilicides are considered as the most promising high-temperature candidate material in that their individual components possess high melting points, high-temperature mechanical property retention, and excellent oxidation resistance. 14 The fabrication of the high-entropy powders is critical for achieving the application of high-entropy disilicides.…”

A step forward from high-entropy ceramics to compositionally complex ceramics: a new perspective

“…In addition to two major classes high-entropy UHTCs (discussed above) that have been extensively studied in the last a few years, high-entropy nitrides [67], silicides [44,45], sulfides [98], fluorides [99], aluminides [43], hexaborides [100], carbonitrides [101], and aluminosilicides [38] have been fabricated. In the broader families of oxide-related HECs, the fabrication of high-entropy magnetoplumbites [87,102], zeolitic imidazolate frameworks [103], ferrites [104], phosphates [18,105], monosilicates [19,20], disilicates [106], and metal oxide nanotube arrays [107] have been reported.…”