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translational energy; Surface temperature dependence寺岡 有殿; 神農 宗徹*; 高岡 毅*; Harries, J.; 岡田 隆太; 岩井 優太郎*; 吉越 章隆; 米田 忠弘*
no journal, ,
The Al(111) surface has been directly nitrided using the supersonic N molecular beam of 2.0 eV at a sample temperature region below 773 K. The nitrogen uptake curves obtained showed an incubation time at the reaction temperature below 473 K, indicating the formation of nitrided local structures (precursors) at the surface. Actually, nitrogen diffusion into aluminium bulk even at 473 K had been already confirmed by a depth profile analysis using angle-resolved photoemission spectroscopy. The Al2p photoemission spectra showed shoulder structures only slightly shifted to higher binding energies, suggesting that sub-nitride components are predominant in the nitride layer. Peak deconvolution of N1s photoemission spectra reveals that the three-coordinated nitrogen (N
) dominates among the four chemical state components (N
: n=1-4) although four-coordinated nitrogen (N
) shares in both Wurtzite and Zinc-Blende type crystal structures.
橋本 雅史; 松岡 雷士; 黒崎 譲; 横山 啓一
no journal, ,
運動量画像分光法を用いたKCl分子の紫外光分解ダイナミクスの測定を初めて行った。得られたK
の画像スペクトルにはリング構造とダンベルのような構造とが存在する。リング構造はKClの解離ステートへの垂直移行によるもので、KClの熱振動分布による薄いリング構造も見られた。一方、ダンベル構造はレーザーパルス幅が100psよりも10psのときに鮮明に見えることなどからKClの二光子直接イオン化によるものと考えられる。過去の研究においてKClの紫外光分解でのCl*/Clチャンネルの分岐比率を約0.3とする報告がなされていたが、われわれの結果ではK + Cl*チャンネルによる信号は存在せず、当該チャンネルが生じないことを示唆している。
吉田 芙美子; 松岡 雷士; 横山 啓一
no journal, ,
Alignment of molecules is a hot topic in the study of quantum control. In many cases, molecules are aligned by rotational coherence created with short laser pulses. Then, aligned molecules lose their coherence through the collision. The de-coherence rate is often measured by the decay of the coherent signal, such as, four-wave mixing, optical Kerr effect, orientation-dependent ionization. However, all these measurements give information only on the coherent state, i.e., off-diagonal elements of the density matrix. To understand the de-coherence process completely, information both on the coherent and incoherent states is required, i.e., whole density matrix including diagonal elements. Therefore, it is worthwhile to develop a technique for measuring both the off-diagonal and diagonal elements simultaneously. As a candidate of such a technique, we explore the potential of the vibrational coherent anti-Stokes Raman scattering (CARS) spectroscopy of aligned molecules.