Dresden 2017 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
HL: Fachverband Halbleiterphysik
HL 86: New Materials
HL 86.8: Vortrag
Freitag, 24. März 2017, 11:45–12:00, POT 112
EPR and DFT investigation of Fe and Fe-Ti doping in LiNbO3 — •Sara Arceiz Casas1, Simone Sanna1, Annamaria Zaltron2, Giacomo Bettella2, Gianluca Pozza2, Cinzia Sada2, and Siegmund Greulich-Weber1 — 1University of Paderborn, Warburger Str. 100, 33098 Paderborn, Germany — 2University of Padova, Via Marzolo 8, 35131 Padova, Italy
The optical properties of Ti4+ indiffused LiNbO3 waveguides are heavily affected by extended and point defects. In particular, even small percentages of unintentional iron doping increase the photorefractive sensitivity of LiNbO3 considerably.
Ti4+ is known to stabilize Fe2+ impurities against oxidation[1], however, neither the defect complexes formed by Fe and Ti nor the mechanisms leading to the optical degrade are known. As a first step towards the understanding of the photorefractive properties of the waveguides, we investigate isolated Fe and Fe-Ti doped LiNbO3 [2,3] by electron paramagnetic resonance (EPR) and density functional theory (DFT).
Signals originating from different defect centers can be discriminated by EPR in Fe doped and Fe-Ti co-doped samples. Corresponding theoretical models are developed within DFT, showing the structural and electronic properties of the observed defects.
[1] V. Gericke, Appl. Phys. B 44, 155 (1987)
[2] O. F. Schirmer, J. Phys.: Cond. Matt. 21, 123201 (2009)
[3] O. F. Schirmer, Phys. Rev. B 83, 165106 (2011)