Structural studies of sub monolayer Sn/Cu(001) structures

Structure determination of the Cu(001)–c(4×4)-Sn surface by low-energy electron diffraction

“…Optimized Debye temperatures of Sn adatoms, substitutional Sn, Cu in the first layer, Cu in the other Cu layers were 130, 150, 220 and 343 K, respectively. It should be noted that model 2 is the same model proposed by the STM observation [11,12] and that Sn coverage is 0.625 ML.…”

“…The determined structure is the same model proposed by the STM observation [11,12]. We present structural parameters, from which we discuss the formation conditions of the c(4 Â 4) structure.…”

“…With increasing coverage, a p(2 Â 6) structure is formed at 0.33 ML. Diffraction patterns of the p(2 Â 6) structure have missing spots, that is, glide planes are present [11]. The subsequently observed phase is a c(4 Â 8) structure, that was discovered recently by scanning tunneling microscopy (STM) studies [10,11].…”

“…Among such adsorption systems, Sn-adsorbed Cu(0 0 1) surfaces have been extensively studied [4][5][6][7][8][9][10][11][12][13][14]. The Cu(0 0 1)-Sn system showed five ordered phases at room temperature in a submonolayer coverage [9,12].…”

“…Upon further deposition of Sn, a c(4 Â 4) structure is observed at about 0.65 ML and an overlayer model was proposed [4]. Recently, a new structure model was proposed from STM observation [11,12]. It was suggested that the c(4 Â 4) structure consists of one substitutional Sn atom and four Sn adatoms per unit cell, but there is no report on its structure determination so far.…”