Rethinking phonons:The issue of disorder

作     者：Hamid Reza Seyf Luke Yates Thomas L.Bougher Samuel Graham Baratunde A.Cola Theeradetch Detchprohm Mi-Hee Ji Jeomoh Kim Russell Dupuis Wei Lv Asegun Henry 

作者机构：George W.Woodruff School of Mechanical EngineeringGeorgia Institute of TechnologyAtlantaGAUSA Heat LabGeorgia Institute of TechnologyAtlantaGAUSA School of Materials Science and EngineeringGeorgia Institute of TechnologyAtlantaGAUSA School of Electrical Engineering and Computer ScienceGeorgia Institute of TechnologyAtlantaGAUSA 

出 版 物：《npj Computational Materials》 (计算材料学（英文）)

年 卷 期：2017年第3卷第1期

页      面：44-51页

核心收录：

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：support from the National Science Foundation through a Career Award(1554050)for A.Henry 

主　　题：alloy character utilize 

摘      要：Current understanding of phonons treats them as plane waves/quasi-particles of atomic vibration that propagate and *** problem is that conceptually,when any level of disorder is introduced,whether compositional or structural,the character of vibrational modes in solids changes,yet nearly all theoretical treatments continue to assume phonons are still *** example,the phonon contributions to alloy thermal conductivity(TC)rely on this assumption and are most often computed from the virtual crystal approximation(VCA).Good agreement is obtained in some cases,but there are many instances where it fails—both quantitatively and ***,we show that the conventional theory and understanding of phonons requires revision,because the critical assumption that all phonons/normal modes resemble plane waves with well-defined velocities is no longer valid when disorder is *** we show,surprisingly,that the character of phonons changes dramatically within the first few percent of impurity concentration,beyond which phonons more closely resemble the modes found in amorphous *** then utilize a different theory that can treat modes with any character and experimentally confirm its new insights.