Raman spectroscopic studies on bismuth nanoparticles prepared by laser ablation

2019-12-07 14:10:03

mode laser Raman nanoparticles phonon

责任者: Onari, S.;Miura, M.;Matsuishi, K. 单位: Inst. of Mater. Sci., Tsukuba Univ., Ibaraki, Japan 来源出处: Applied Surface Science(Appl. Surf. Sci. (Netherlands)),30 Sept. 2002,197-198():615-18 摘要: Bi nanoparticles are prepared by means of laser ablation in Ar atmosphere (0.2-10 Torr) with KrF (248 nm) excimer laser of the power 200 mJ. The size of the Bi particles estimated by TEM measurements is in the range 3-10 nm. Raman active Eg mode shifts to a higher frequency and becomes broader for a sample prepared in a lower pressure of Ar atmosphere. However, the peak frequency and the bandwidth of A1g mode show almost no change with the change of the particle size. These experimental results can be well explained by a phonon confinement model of Campbell and Fauchet by taking the phonon dispersion properties that the Eg mode of the crystal has a large dependence on the wave numbers near the Γ point, but the A1g mode is rather independent of the phonon wave numbers 关键词: bismuth;laser ablation;nanoparticles;nanotechnology;particle size;phonon dispersion relations;phonon spectra;Raman spectra;spectral line shift;transmission electron microscopy;Raman spectroscopic studies;bismuth nanoparticles;laser ablation technique;Bi nanoparticles;Ar atmosphere;excimer laser;TEM;transmission electron microscopy;Raman scattering;higher frequency;lower pressure;bandwidth;A1g mode;particle size;phonon confinement model;phonon dispersion properties;Eg mode;phonon wave numbers;248 nm;200 mJ;0.2 to 10 torr;3 to 10 nm;Bi;Ar