Electron-phonon interactions in insulating nanoparticles: Eu2O3

2019-11-07 08:24:01

modes hole phonon interactions linewidth

责任者: Meltzer, R.S.;Hong, K.S. 单位: Dept. of Phys. & Astron., Georgia Univ., Athens, GA, USA 来源出处: Physical Review B (Condensed Matter)(Phys. Rev. B, Condens. Matter (USA)),2000/02/01,61(5):3396-403 摘要: The temperature and particle size dependencies of the linewidth of spectral holes burned in the 7F0→5D0 transition of Eu3+ ions in Eu2O3 are calculated and compared with experiment. The power-low temperature behavior ~T7, well-known experimentally and theoretically for the bulk, is observed to be strongly weakened to ~T3 for the nanoparticles. A calculation is performed that assumes a two-phonon Raman-scattering mechanism involving the discrete phonon modes of a homogeneous nanoparticle with stress-free boundary conditions. The experimental results are successfully described assuming that the phonon modes broaden with frequency as ~ω2. A quantitative comparison of the calculations with experiment allows the determination of the linewidth of the phonon resonances of the nanoparticles. The calculations predict that the size dependence of the hole linewidth is ~D-2.5, in close agreement with experiment 关键词: electron-phonon interactions;europium compounds;nanostructured materials;optical hole burning;particle size;phonon spectra;phonon-phonon interactions;Raman spectra;spectral line breadth;electron-phonon interactions;insulating nanoparticles;Eu2O3;particle size dependence;temperature dependence;linewidth;spectral hole burning;Eu3+ ions;power-law temperature behavior;two-phonon Raman-scattering mechanism;discrete phonon modes;stress-free boundary conditions;phonon modes;phonon resonances;hole linewidth