Towards a refinement of bonding features in MgO from directional Compton profiles
✍ Scribed by C Fluteaux; J.M Gillet; P Becker
- Publisher
- Elsevier Science
- Year
- 2000
- Tongue
- English
- Weight
- 219 KB
- Volume
- 61
- Category
- Article
- ISSN
- 0022-3697
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✦ Synopsis
Adhesive properties of metals on oxide substrates, such as MgO, critically depend on the effective covalent character of metal-oxygen. In ionic solids (J.M. Gillet, P. Becker, G. Loupias, Acta Cryst. A 51 (1995) 405-413) the anisotropy among directional Compton profiles was shown to be strongly dependent upon the iono-covalent character of cohesive interactions. A systematic study of momentum density was thus undertaken for MgO, both experimental and theoretical. Reliable DCPs were obtained at ESRF, anisotropies being in fair agreement with Hartree-Fock calculations. In order to refine coupling parameters among valence orbitals, a three-dimensional (3D) reconstruction of momentum density is necessary. Various approaches are considered: besides spherical harmonics reconstruction, we propose a simple and efficient Gaussian fit of DCPs, followed by an extrapolation to the 3D momentum density. Preliminary results are discussed.