Phonon-phonon interactions in Ce0.85Gd0.15O2-δ nanocrystals studied by Raman spectroscopy
Phonon-phonon interactions in Ce0.85Gd0.15O2-δ nanocrystals studied by Raman spectroscopy
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DOI：
10.1002/jrs.2177
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发表时间：
2009-06-01
影响因子：
2.5
通讯作者：
Popovic, Z. V.
中科院分区：
文献类型：
--
作者：
Askrabic, S.;Dohcevic-Mitrovic, Z. D.;Popovic, Z. V.
通过拉曼光谱在 293-1100 K 的温度范围内检查了 Gd 掺杂二氧化铈纳米晶体的声子-声子相互作用和相稳定性。基于尺寸、不均匀应变和非谐效应的声子约束模型（PCM）用于正确描述该系统中的非谐相互作用。与较大颗粒相比，尺寸和非谐波效应之间的相互作用影响了纳米颗粒中不同的声子衰变通道。逐渐冷却至室温 (RT) 后，拉曼研究揭示了该系统中的相分离，表明热处理后 Ce0.85Gd0.15O2-delta 纳米晶体的相不稳定。还通过拉曼光谱研究了 Ce0.85Gd0.15O2-delta 纳米晶样品热处理过程中外在（内在）氧空位的浓度。版权所有 (C) 2009 John Wiley & Sons, Ltd.
Phonon-phonon interactions and phase stability of Gd-doped ceria nanocrystals were examined over the temperature range 293-1100 K by Raman spectroscopy. The phonon confinement model (PCM) based on size, inhomogeneous strain and anharmonic effects was used to properly describe the anharmonic interactions in this system. The interplay between size and anharmonic effects influenced different phonon decay channels in nano grains than in larger grains. After the gradual cooling down to room temperature (RT), the Raman study revealed the phase separation in this system pointing to the phase instability of Ce0.85Gd0.15O2-delta nanocrystals after heat treatment. The concentration of extrinsic (intrinsic) oxygen vacancies was also studied by Raman spectroscopy during the heat treatment of the Ce0.85Gd0.15O2-delta nanocrystalline sample. Copyright (C) 2009 John Wiley & Sons, Ltd.