High-Entropy van der Waals Materials Formed from Mixed Metal Dichalcogenides, Halides, and Phosphorus Trisulfides

Abstract

The charge, spin, and composition degrees of freedom in a high-entropy alloy endow it with tunable valence and spin states, infinite combinations, and excellent mechanical performance. Meanwhile, the stacking, interlayer, and angle degrees of freedom in a van der Waals material bring to it exceptional features and technological applications. Integration of these two distinct material categories while keeping their merits would be tempting. On the basis of this heuristic thinking, we design and explore a new range of materials (i.e., dichalcogenides, halides, and phosphorus trisulfides) with multiple metallic constitutions and intrinsic layered structure, which are coined as high-entropy van der Waals materials. Millimeter-scale single crystals with a homogeneous element distribution can be efficiently acquired and easily exfoliated or intercalated in this materials category. Multifarious physical properties such as superconductivity, magnetic ordering, metal−insulator transition, and corrosion resistance have been exploited. Further research based on the concept of high-entropy van der Waals materials will enrich the highthroughput design of new systems with intriguing properties and practical applications.

High Entropy van der Waals Materials

“…Cubic A6B12C8 Td AuTe2Se4/3 [29,30] Figure 2. Crystal growth and element distribution of HEX materials [17,19] .…”

“…Figure 4. The intercalation of HEX [17] . (a) X-ray diffraction patterns of polycrystalline (black), single-crystalline (orange), and potassium-intercalated (blue) (TiVCrNbTa)S2.…”

Bottom-up synthesis of 2D layered high-entropy transition metal hydroxides

“…Hosono et al developed a mechanical exfoliation method to synthesize a series of high-entropy van der Waals 2D materials (dichalcogenides, halides, and phosphorus trisulfides) with an intriguing set of properties. 46 Wang et al developed high-entropy layered double hydroxides (HE-LDH) (FeAlCrCoNiZnCu)–OH intercalated with CO 3 2− by a hydrothermal method and exfoliated them to ultrathin defective nanosheets with a diameter of 50 nm with argon plasma. 42 Wang et al also reported the synthesis of spinel-type high-entropy oxide (FeCrCoNiCu) 3 O 4 nanosheets with diameters up to 100 nm by oxygen plasma exfoliation of HE-LDH.…”

Synthesis and Characterization of High-Entropy-Alloy-Type Layered Telluride MBi2Te4 (M = Ag, In, Sn, Pb, Bi)

“…The results suggest that the HEA states would affect the superconducting gap opening. More recently, HEA-type van-der-Waals layered superconductors were designed and synthesized [ 11 ]. For the cases of three-dimensional structures, we have investigated the effect of the introduction of HEA sites in NaCl-type M Te [ 12 , 13 , 14 ] and A15-type Nb 3 X and V 3 X [ 15 , 16 ].…”