Low-temperature surface phase and phase transition of physisorbed oxygen on the Ag(111) surface
Low-temperature surface phase and phase transition of physisorbed oxygen on the Ag(111) surface
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Ag(111)表面低温表面相及物理吸附氧的相变
DOI：
10.1103/physrevb.84.064128
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
T.Okano,K.Fukutani
中科院分区：
文献类型：
--
作者：
Y.Kazama;M.Matsumoto;T. Sugimoto;T.Okano,K.Fukutani
用低能电子衍射和热脱附谱研究了O在Ag（111）表面的低温物理吸附。TDS显示，三个解吸功能开发在31.5，35，和38 K取决于O覆盖。在低于0.8 L的低剂量下，在38 K下观察到TDS峰，LEED显示出11图案，表明无序相。在0.8 ~ 3L剂量范围内，LEED的时相为（1.100.231.55），而在3L以上剂量范围内，则为（）。两相都与基体不相称。- O的结构被认为是一个横截面的-O固相的O-O键接近平行于表面。的-O不可逆的变化，在25 K的无序结构，这可能指向一个玻璃化转变，由于挫折。另一方面，高覆盖度相的结构被认为是-O固相的平面，其中O-O键垂直于表面。O相在26.5K发生可逆的有序-无序相变。
Physisorption of Oon the Ag(111) surface at low temperature was studied by low-energy electron diffraction and thermal-desorption spectroscopy (TDS). TDS revealed that three desorption features develop at 31.5, 35, and 38 K depending on the Ocoverage. At a low dosage below 0.8 L where a TDS peak is observed at 38 K, LEED showed a 11 pattern suggesting a disordered phase. While a (1.100.231.55) pattern designated as thephase was observed in LEED at a dosage between 0.8 and 3 L, a () pattern designated asphase appeared above 3 L. Both phases are incommensurate with the substrate. The structure of-Ois considered to be a cross section of the-Osolid phase with the O–O bond near parallel to the surface. The-Oirreversibly changes to a disordered structure at 25 K, which might point toward a glass transition due to frustration. The structure of the high coveragephase, on the other hand, is considered to be theplane of the-Osolid phase with the O–O bond perpendicular to the surface. The-Ophase undergoes a reversible order-disorder phase transition at 26.5 K.