The search for new materials via compositional exploration has recently led to the discovery of entropy stabilized and high entropy ceramics. The chemical diversity in the cation sublattice of high entropy ceramics has led to many enhanced properties and applications such as reversible energy storage, low temperature water splitting, amorphous-like thermal transport in crystalline solids and enhanced mechanical properties. This work describes the synthesis and mechanical properties of high entropy (HfNbTaTiZr)C_x thin films as a function of carbon content. The nature of the bonding and microstructure evolves as the material transforms from metallic to ceramic to nanocomposite with variations in the quantity and types of carbon, yielding large variations in the film hardness. Through multiple characterization techniques and first principles investigations, we separate the roles of microstructure and bonding characteristics in the mechanical property development of (HfNbTaTiZr)C_x thin films. This study presents a strategy to establish the bonding, structure, and property relationships in chemically disordered high entropy ceramics, largely based on the relative populations of filled or empty antibonding states for which there are new abilities to do so in high configurational entropy systems that exhibit high solubility of diverse cations while retaining rocksalt structure.

通过成分探索寻找新材料最近导致了熵稳定和高熵陶瓷的发现。高熵陶瓷阳离子亚晶格中的化学多样性导致了许多增强的性能和应用，例如可逆能量存储、低温水分解、晶体固体中的非晶状热传输和增强的机械性能。这项工作描述了高熵 (HfNbTaTiZr)C _x的合成和机械性能薄膜作为碳含量的函数。随着材料从金属转变为陶瓷再到纳米复合材料，随着碳的数量和类型的变化，粘合和微观结构的性质发生了变化，从而产生了薄膜硬度的巨大变化。通过多种表征技术和第一性原理研究，我们分离了微观结构和键合特性在 (HfNbTaTiZr)C _x机械性能发展中的作用薄膜。本研究提出了一种在化学无序高熵陶瓷中建立键合、结构和性质关系的策略，主要基于填充或空反键合状态的相对种群，在高构型熵系统中具有这样做的新能力，表现出多种阳离子的高溶解度，同时保留岩盐结构。