Pauls C, Christmann K
Institut für Chemie und Biochemie der FU Berlin, Bereich Physikalische und Theoretische Chemie, Takustrasse 3, D-14195 Berlin, Germany.
J Phys Condens Matter. 2009 Apr 1;21(13):134012. doi: 10.1088/0953-8984/21/13/134012. Epub 2009 Mar 12.
We have deposited Au films in ultra-high vacuum onto a rhenium ([Formula: see text]) surface in submonolayer and multilayer concentrations and studied them by means of low- and medium-energy electron diffraction in the temperature range between 300 and 800 K. In the submonolayer range, Au forms several low-energy electron diffraction (LEED) phases, namely, a (1 × 3), a (1 × 4), a (1 × 5) and a (1 × 6) phase, consisting of one-dimensionally ordered Au chains in the [[Formula: see text]] direction, until the formation of a complete pseudomorphic monolayer is indicated by a (1 × 1) LEED phase. In the multilayer regime, a (1 × 8) LEED phase appears over a surprisingly wide coverage range from about two to at least eight monolayers, which we interpret as a hexagonal uniaxially compressed reconstructed Au overlayer on pseudomorphically grown hexagonal close-packed gold layers. In order to get access to absolute Au coverages, we have performed LEED (I,V) measurements and carried out a LEED structure determination for the (1 × 1) phase. We propose the formation of a full Au monolayer in which both the Re trough and top-row sites are being covered by Au atoms. The data are discussed and compared with those from previous studies on related systems.
我们在超高真空中将金膜沉积到铼([化学式:见正文])表面,沉积浓度为亚单层和多层,并在300至800 K的温度范围内通过低能和中能电子衍射对其进行研究。在亚单层范围内,金形成了几种低能电子衍射(LEED)相,即(1×3)、(1×4)、(1×5)和(1×6)相,由在[[化学式:见正文]]方向上一维有序的金链组成,直到(1×1)LEED相表明形成了完整的赝形单层。在多层体系中,(1×8)LEED相出现在从约两个到至少八个单层的惊人宽的覆盖范围内,我们将其解释为在赝形生长的六方密堆积金层上的六方单轴压缩重构金覆盖层。为了获得绝对的金覆盖率,我们进行了LEED(I,V)测量,并对(1×1)相进行了LEED结构测定。我们提出形成一个完整的金单层,其中铼的凹槽和顶排位置都被金原子覆盖。对数据进行了讨论,并与先前对相关体系的研究数据进行了比较。