Przystawik Andreas, Radcliffe Paul, Diederich Thomas, Döppner Tilo, Tiggesbäumker Josef, Meiwes-Broer Karl-Heinz
Institut für Physik, Universität Rostock, 18051 Rostock, Germany.
J Chem Phys. 2007 May 14;126(18):184306. doi: 10.1063/1.2723087.
Photoelectron spectra of neutral silver trimers, grown in ultracold helium nanodroplets, are recorded after ionization with laser pulses via a strong optical resonance of this species. Varying the photon energy reveals that direct vertical two-photon ionization is hindered by a rapid relaxation into the lower edge of a long-living excited state manifold. An analysis of the ionization threshold of the embedded trimer yields an ionization potential of 5.74+/-0.09 eV consistent with the value found in the gas phase. The asymmetrical form of the electron energy spectrum, which is broadened toward lower kinetic energies, is attributed to the influence of the matrix on the photoionization process. The lifetime of the excited state was measured in a two-color pump-probe experiment to be 5.7+/-0.6 ns.
通过该物种的强光学共振，用激光脉冲对超冷氦纳米液滴中生长的中性银三聚体进行电离后，记录其光电子能谱。改变光子能量表明，直接垂直双光子电离受到快速弛豫到长寿命激发态流形下边缘的阻碍。对嵌入三聚体的电离阈值进行分析，得出电离势为5.74±0.09 eV，与气相中的值一致。电子能谱的不对称形式，向较低动能方向展宽，归因于基质对光电离过程的影响。在双色泵浦-探测实验中测得激发态的寿命为5.7±0.6 ns。
