Abstract SnO2 nanoparticles are of critical importance owing to their necessity for fundamental studies and highly attractive applications in optoelectronic devices and photocatalytic activities. In this study Raman spectroscopy was rigorously employed to investigate the effect of low concentrations of cobalt doping in rutile SnO2 nanoparticles. The effect of annealing temperature and laser power dependent molecular vibrations was used to directly realize the localized microstructural changes and phonons interaction within the lattice. A large broadening and shifting towards the lower wavenumber side in the Raman spectra for A1g and B2g modes of vibration were observed. This was mainly attributed to microstructural changes, maximum possible quasiharmonic shift and a large proportion from pure anharmonic shifts as a function of increasing laser power. Two approaches were adopted to calculate the localized temperature that has increased due to laser heating during the Raman measurements in the samples. In a more feasible and reliable approach the full with at half maxima (FWHM) broadening and frequency shifting as a function of laser power were directly compared with the previously reported experimental results. In another approach the well-known Klement model based on the kinematics of three-phonon processes was also used to determine the localized temperature.

中文翻译：

---

通过激光功率相关拉曼光谱观察 Co 掺杂 SnO2 纳米粒子中的声子非谐性和微观结构变化

摘要 SnO2 纳米粒子由于其对基础研究的必要性以及在光电器件和光催化活性中极具吸引力的应用而具有至关重要的意义。在这项研究中，拉曼光谱被严格用于研究金红石 SnO2 纳米粒子中低浓度钴掺杂的影响。退火温度和激光功率相关的分子振动的影响被用来直接实现晶格内的局部微观结构变化和声子相互作用。观察到 A1g 和 B2g 振动模式的拉曼光谱中大的展宽和向低波数侧移动。这主要归因于微观结构的变化，最大可能的准谐波位移和大部分来自纯非谐波位移作为增加激光功率的函数。采用两种方法来计算在样品的拉曼测量期间由于激光加热而增加的局部温度。在更可行和更可靠的方法中，将全半最大值 (FWHM) 加宽和频移作为激光功率的函数与先前报告的实验结果进行直接比较。在另一种方法中，著名的基于三声子过程运动学的 Klement 模型也用于确定局部温度。在更可行和更可靠的方法中，将全半最大值 (FWHM) 加宽和频移作为激光功率的函数与先前报告的实验结果进行直接比较。在另一种方法中，著名的基于三声子过程运动学的 Klement 模型也用于确定局部温度。在更可行和更可靠的方法中，将全半最大值 (FWHM) 加宽和频移作为激光功率的函数与先前报告的实验结果进行直接比较。在另一种方法中，著名的基于三声子过程运动学的 Klement 模型也用于确定局部温度。