Size-dependent modifications of the first-order Raman spectra of nanostructured rutile TiO 2
Size-dependent modifications of the first-order Raman spectra of nanostructured rutile TiO 2
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DOI：
10.1103/physrevb.77.195414
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发表时间：
2008-05
影响因子：
3.7
通讯作者：
V. Swamy
中科院分区：
文献类型：
--
作者：
V. Swamy
分析了一组金红石纳米晶的拉曼光谱随晶体尺寸的变化，并与已报道的镶嵌在薄膜中的纳米金红石/微晶的拉曼光谱特征进行了比较。在各种金红石纳米结构中，强度和模式显示出不同的尺寸依赖关系。观察到纳米粉末样品的拉曼频率红移、非对称峰展宽和强度/线宽比随微晶尺寸减小而减小的现象与声子限制相一致。对于纳米金红石薄膜，非系统的拉曼光谱修正与声子限制不一致，这表明内在的结晶学或外部基质影响可能会干扰和叠加限制效应。
The crystallite-size-dependent Raman spectral modifications observed for a suite of rutilenanocrystals are analyzed and compared to the characteristics of the Raman spectra that were reported for nanoscale rutiledomains/crystallites embedded in thin films. The strongandmodes display disparate size dependencies in the various rutile nanostructures. The redshifts of the Raman frequencies, asymmetric peak broadening, and intensity/linewidth ratio reductions with decreasing crystallite size observed for nanopowder samples are consistent with phonon confinement. The nonsystematic Raman spectral modifications that are inconsistent with phonon confinement documented for the nanoscale rutile within thin films suggest that intrinsic crystallographic or extrinsic matrix influences can interfere and overprint the confinement effects.