Electric field gradient in FeTiO3 by nuclear magnetic resonance and ab initio calculations

• Published in: Journal of physics. Condensed matter 2011-05, Vol.23 (20), p.205503-205503
• Main Authors: Procházka, V, Štěpánková, H, Chlan, V, Tuček, J, Čuda, J, Kouřil, K, Filip, J, Zbořil, R
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Magnetic resonances and relaxations in condensed matter, mössbauer effect; Mössbauer effect; other γ-ray spectroscopy; Nuclear magnetic resonance and relaxation; Physics
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/23/20/205503

Temperature dependence of nuclear magnetic resonance (NMR) spectra of (47)Ti and (49)Ti in polycrystalline ilmenite FeTiO(3) was measured in the range from 5 to 300 K under an external magnetic field of 9.401 T. NMR spectra collected between 300 and 77 K exhibit a resolved quadrupole splitting. The electric field gradient (EFG) tensor was evaluated for Ti nuclei and the ratio of (47)Ti and (49)Ti nuclear quadrupole moments was refined during the fitting procedure. Below 77 K, the fine structure of quadrupole splitting disappears due to the enormous increase of anisotropy. As a counterpart, ab initio calculations were performed using full potential augmented plane waves + local orbitals. The calculated EFG tensors for Ti and Fe were compared to the experimental ones evaluated from NMR and the Mössbauer spectroscopy experiments.