以基於密度泛函理論的VASP第一原理計算，研究多主元素碳化物和碳氮化物之組成與機械性質，目的搜尋應用於高耐磨耗、低摩擦係數之硬質薄膜材料。研究發現IB-VIB族過渡金屬元素是這些多主元素陶瓷的候選元素，對元素隨機分佈的多元素結構進行結構優化、熱力學、機械性質與電荷特性計算。透過幾個經驗與理論歸納公式評估耐磨耗與低摩擦特性。結果顯示這些化合物之合成過程為一吸熱過程，且這些多元素陶瓷為符合立方體結構機械穩定性之脆性陶瓷材料。不同成份組合的MPEC(N)s展現了不同的機械性質，從電荷分析結果推論差異可能源自陶瓷中原子電荷交換變化，以及元素族群價電子組態差異之影響。透過研究不同成份組合之機械性質與相穩定，本研究可做為一個硬質薄膜材料之設計與選擇的參考。

Composition and mechanical properties of multi-principal element carbides and carbonitrides are studied by first-principles calculations via VASP based on density functional theory. The main goal is to survey compositions of multi-principal element carbides (MPECs) and carbonitrides (MPECNs) for high wear resistance and low friction applications. It is found out that transition metals elements of IB - VIB group are promising constituent elements of these multi-principal element ceramics. Structure optimization, thermodynamics, mechanical property, and electronic property calculations are performed on multi-principal element structure with random elements distribution. Wear resistance and low friction property are estimated through several empirical and theoretical criteria. The results indicate that the formation of MPEC(N)s is an endothermic process. Also, these MPEC(N)s are brittle material with mechanical stability of cubic structure. The different composition of MPEC(N)s show different mechanical property which may be due to the electron transfer between atoms and atomic property difference in between element groups.

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