Details

Autor(en) / Beteiligte

• Petkov, Valeri
• Billinge, Simon J. L
• Heising, Joy
• Kanatzidis, Mercouri G

Titel

Application of Atomic Pair Distribution Function Analysis to Materials with Intrinsic Disorder. Three-Dimensional Structure of Exfoliated-Restacked WS 2 :  Not Just a Random Turbostratic Assembly of Layers

Ist Teil von

• Journal of the American Chemical Society, 2000-11, Vol.122 (47), p.11571-11576

Ort / Verlag

American Chemical Society

Erscheinungsjahr

2000

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The three-dimensional structure of metastable exfoliated-restacked WS2 (r-WS2) has been determined by the atomic pair distribution function (PDF) technique. We show that the structure of r-WS2 is not a random turbostratic assembly of layers, as previously thought, but it can be better regarded as a monoclinic structure with considerable intrinsic disorder. At room temperature, the atomic-scale structure of r-WS2 is well described in the space group P1121 of the monoclinic system with four formula units in the cell, and lattice parameters a = 3.270(5) Å, b = 5.717(5) Å, c = 12.309(5) Å, and γ = 88.43°. Analysis of the X-ray scattering data, collected with Synchrotron radiation (λ = 0.202 Å) over a wide scattering angle, shows that the metastable material is built of layers of distorted (WS6) octahedral units, in contrast to hexagonal 2H-WS2 which is built of layers of perfect (WS 6 ) trigonal prisms. A characteristic structural feature of the restacked material is that W atoms within a single layer form zigzag chains along the a axis of the unit cell via short metal−metal bonds of length 2.77(1) and 2.85(1) Å, in agreement with previous two-dimensional electron diffraction studies.