Structure of the Al13Co4(100) surface: Combination of surface x-ray diffraction and ab initio calculations

Emilie Gaudry (1) , C Chatelier (1, 2) , G G Mcguirk (1) , L L Serkovic Loli (1) , Marie-Cécile de Weerd (1) , Julian Ledieu (1) , Vincent Fournée (1) , R N Felici (3) , J Drnec (3) , G Beutier (4) , M N de Boissieu (4)

1 IJL - Institut Jean Lamour
2 ENSMN - Ecole Nationale Supérieure des Mines de Nancy
3 ESRF - European Synchrotron Radiation Facility
4 SIMaP - Science et Ingénierie des Matériaux et Procédés

The structure of the quasicrystalline approximant Al13Co4(100) has been determined by surface x-ray diffraction (SXRD) and complementary density-functional-theory (DFT) calculations. Thanks to the use of a two-dimensional pixel detector, which speeds up the data acquisition enormously, an exceptionally large set of experimental data, consisting of 124 crystal truncation rods, has been collected and used to refine this complex structure of large unit cell and low symmetry. Various models were considered for the SXRD analysis. The best fit is consistent with a surface termination at the puckered type of planes but with a depletion of the protruding Co atoms. The surface energy of the determined surface model was calculated using DFT, and it takes a rather low value of 1.09 J/m 2. The results for the atomic relaxation of surface planes found by SXRD or DFT were in excellent agreement. This work opens up additional perspectives for the comprehension of related quasicrystalline surfaces.

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Matériaux

Emilie Gaudry, C Chatelier, G G Mcguirk, L L Serkovic Loli, Marie-Cécile de Weerd, et al.. Structure of the Al13Co4(100) surface: Combination of surface x-ray diffraction and ab initio calculations. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2016, 94, pp.165406. ⟨10.1103/PhysRevB.94.165406⟩. ⟨hal-01379675⟩