Abstract
Optical absorption, conversion electron Mössbauer spectroscopy and transmission electron microscopy have been combined to study high dose iron implantation effects in MgO single crystals. After implantation at room temperature with 6 × 10 16 ions cm −2, large concentrations of defects are observed in the anionic sublattice (F, F + and F 2 centers) and in the cationic sublattice (V −-centers) as well as superparamagnetic iron precipitates (∼20 Å in diameter), and Fe 2+ ions. The thermal annealing effects at 700°C are to anneal all the point defects previously mentioned and to convert the iron mainly into Fe 3+ ions. The major fraction of these species is aggregated into Fe 2O 3 particles, while a smaller fraction part is substitutionally located in the MgO matrix. A significant change is observed after annealing at 800°C. At this stage the aggregates are sufficiently large (∼200 Å) to be observed well by electron microscopy. The electron diffraction pattern reveals the formation of a spinel ferrite: MgFe 2O 4 or Fe 3O 4. The annealing effect at a temperature higher than 800°C is to increase the ferrite particle size (∼300 Å at 900°C).
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
