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With the improvement of human ability to produce materials,alloy coatings have evolved from containing simple composition to containing complex compositions.And containing multiple major components causes the high-entropy alloy coatings to present high thermal stability and wear resistance,as well as excellent fatigue resistance,high temperature tensile property,corrosion resistance and magnetic properties,and these excellent properties make them exceed the application range of conventional alloy coatings and bring them many potential application prospects.The study of the relationship between microstructure and properties of high-entropy alloy coatings is important for the further development of high-entropy alloy coating materials with better performance.In this paper,the characteristics and application area of conventional high-entropy alloy coatings,refractory high-entropy alloy coatings,composite high-entropy alloy coatings and lightweight high-entropy alloy coatings were reviewed,and the effects of the types of high-entropy alloy coatings on their mechanical properties,frictional properties and corrosion resistance were introduced,and finally an outlook on the development of high-entropy alloy coatings was provided.

This article reports a novel lead‐free phase‐transition material (C8H10ClN)2SnCl6 (1), which undergoes a high‐temperature phase change at close to 377 K. The multi temperature powder X‐ray diffraction (PXRD) also confirmed the phase transition occurred in compound 1. Significantly, compound 1 produces light emission at 452 nm. Variable temperature fluorescence studies indicate that the spectral emission maximum of compound 1 remains substantially fixed at 452 nm with increasing temperatures, implying the presence of a certain degree of photoluminescence stability in compound 1. Furthermore, compound 1 is characterized by exceptional semiconductor attributes, possessing a band gap of 3.76 eV. This pioneering study presents an innovative option for optimizing the growth and practical implementation of Sn (IV)‐based organic‐inorganic hybrid perovskite phase‐transition materials, and offers a strategic avenue to create novel lead‐free, eco‐friendly materials. [ABSTRACT FROM AUTHOR]

Organic–inorganic hybrid metal halides for high-temperature phase transition have become increasingly popular owing to their wide operating temperature range in practical applications, e.g., energy storage, permittivity switches and opto-electronic devices. This paper describes the subtle assembly of two new hybrid perovskite crystals, [Cl-C6H4-(CH2)2NH3]2CdX4 (X = Br 1; Cl 2), undergoing high-T reversible phase transformations around 335 K/356 K. Differential scanning calorimetry (DSC), differential thermal analysis (DTA) and VT PXRD tests uncover their reversible first-order phase transition behaviors. Furthermore, the compounds exhibit switchable dielectricity near T, making them potential dielectric switching materials. Hirshfeld surface analysis well discloses a distinct difference in hydrogen-bonding interaction between 1 and 2. UV spectra and computational analysis demonstrate that the compounds are a type of direct-band-gap semiconductor. This research will contribute an effective approach to the structure and development of multifunctional molecular hybrid crystals. [ABSTRACT FROM AUTHOR]

Organic‐inorganic hybrid multifunctional materials have received significant attention due to their potential applications in smart devices such as phase‐change memory (PCM), resistive random‐access memory (ReRAM). Yet, devices application requires achieving a balance between fast switching speeds, long‐term stability, and high cycling endurance in materials still facing difficulties. Herein, we report two hybrid phase transition compounds: (CMQ)BiCl5(CMQ=Chloromethyl Quinuclidin‐3‐one) (1) and (FMQ)2SbBr5(FMQ=Fluoromethyl Quinuclidin‐3‐one) (2), both two compounds exhibit high phase transition temperature, dual‐stable behavior in dielectric during reversible phase transition process. Notably, 1 exhibit small dielectric change after multiple dielectric state switching. Furthermore, investigate the influence of halogen substitution (F to Cl) for compound properties, which show an Increasing transition temperature (9 K) and raising structural dimension (0D to 1D). Additionally, using first principles, analyze the electronic structure of 1 and find that it has a 3.4 eV wide bandgap, closing to GaN semiconductor (3.4 eV). This work provides a new insight into developing the next‐generation phase transition compounds and chemical modification enhances material performance. [ABSTRACT FROM AUTHOR]

Multifunctional materials are an attractive research area. Organic‐inorganic hybrid perovskites are widely used in the design of these materials due to their rich properties and flexible composition. It is easy to obtain more photoelectric properties by introducing chiral groups as ligands. In this work, we synthesized chiral one‐dimensional organic‐inorganic hybrid perovskites, namely (R/S‐3‐HP)PbBr3 (1R/1S) (3‐HP=3‐hydroxy‐piperidine). The enantiomer compounds undergo reversible phase transition at 349/336 K. Under the excitation light of 339 nm, 1R and 1S have a wide emission peak at 635 nm, showing orange light. In addition, the indirect bandgap is 3.29 eV and the SHG intensity is comparable to that of KDP. This work provides a way to design multifunctional chiral perovskite materials. [ABSTRACT FROM AUTHOR]