Temperature-dependent La- and Al-induced dipole behavior monitored by femtosecond pump/probe photoelectron spectroscopy
Temperature-dependent La- and Al-induced dipole behavior monitored by femtosecond pump/probe photoelectron spectroscopy
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DOI：
10.1063/1.3374883
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发表时间：
2010-03
影响因子：
4
通讯作者：
H. Arimura;R. Haight;S. Brown;A. Kellock;A. Callegari;M. Copel;Heiji Watanabe;V. Narayanan;T. Ando
中科院分区：
文献类型：
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作者：
H. Arimura;R. Haight;S. Brown;A. Kellock;A. Callegari;M. Copel;Heiji Watanabe;V. Narayanan;T. Ando
利用飞秒泵浦/探测光电子能谱系统地研究了热平衡对La和Al诱导的偶极子的影响。我们发现，La诱导的偶极子需要在300 °C下退火以完全激活，而Al诱导的偶极子在较低温度下激活，但需要在300 °C下退火以消除抵消的片状电荷。当La和Al原子在SiO2表面共存时，在600 °C以上的温度下发生硅酸盐形成反应后，La诱导的偶极子占主导地位。这种现象归因于La和Al诱导的偶极子的不同性质，即，远程和短程。
The impact of thermal budget on La- and Al-induced dipoles is systematically investigated by femtosecond pump/probe photoelectron spectroscopy. We find that the La-induced dipole requires annealing at 300 °C for complete activation, whereas the Al-induced dipole is activated at the lower temperature but requires annealing at 300 °C to eliminate a counteracting sheet charge. When La and Al atoms coexist on a SiO2 surface, the La-induced dipole becomes dominative after a silicate-forming reaction at the temperature above 600 °C. This phenomenon is attributed to the different natures of the La- and Al-induced dipoles, i.e., long-range and short-range.