Recent Raman data on nanocrystallite arrays are revised within the microscopic theory for Raman peaks positions and broadening (linewidth). The theory combines the elasticity theory-like approach for optical phonons used in order to evaluate the Raman peaks structure and the Green's function method applied for the phonon lines broadening. These theories are supported by the atomistic calculations within the dynamical matrix method for optical phonons and by the bond polarization model used to calculate the Raman intensities. The experimental data on four various nanopowders are analyzed with the use of this theory. The large width of the Raman peak in nanoparticles as compared with the corresponding peak in bulk materials and the width inverse dependence on the particle size previously observed by other researchers are explained within the framework of the theory. It is shown that the theory is capable to extract confidently from the Raman data four important microscopic characteristics of the nanopowder including the mean particle size, the variance of the particle size distribution function, the strength of intrinsic disorder in the particle, and the effective faceting number that parameterizes the particle shape.

中文翻译：

---

无序非极性晶体粉末中拉曼散射微观理论的台架试验：纳米金刚石及其他

最近关于纳米微晶阵列的拉曼数据在拉曼峰位置和加宽（线宽）的微观理论中进行了修订。该理论结合了用于评估拉曼峰结构的类似弹性理论的光学声子方法和用于声子线加宽的格林函数方法。这些理论得到了光学声子动力学矩阵方法中的原子计算和用于计算拉曼强度的键极化模型的支持。应用该理论分析了四种不同纳米粉体的实验数据。与散装材料中的相应峰相比，纳米颗粒中拉曼峰的大宽度以及其他研究人员先前观察到的宽度与粒径的负相关在该理论框架内进行了解释。结果表明，该理论能够从拉曼数据中可靠地提取纳米粉体的四个重要微观特征，包括平均粒径、粒径分布函数的方差、颗粒内在无序的强度和有效刻面参数化粒子形状的数字。