SAIP2014

First-principles study of Fe-doped MgO

9 Jul 2014, 17:10

1h 50m

D Ring ground level

Board: G.412

Poster Presentation Track G - Theoretical and Computational Physics Poster2

Speaker

Dr Mahlaga Molepo (University of Pretoria)

Apply to be<br> considered for a student <br> &nbsp; award (Yes / No)?

No

Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?

No

Abstract content <br> &nbsp; (Max 300 words)<br><a href="http://events.saip.org.za/getFile.py/access?resId=0&materialId=0&confId=34" target="_blank">Formatting &<br>Special chars</a>

We present a theoretical investigation on the structural, thermodynamic and magnetic properties of substitutional iron impurity in rocksalt magnesium oxide, (MgO: Fe_Mg) as a candidate dilute magnetic semiconductor for spintronic applications. Ab initio pseudopotential density functional calculations were performed for Fe in MgO at various charge and spin states in order to determine the most stable configurations. The generalized gradient approximation with the on-site Hubbard potential correction was used. We find that the double positively charged (Fe⁺²) with high spin (S=2) state and O_h symmetry center is the most energetically favorable, while the low spin (S=1) state with D_4h symmetry center is 0.63 eV higher in energy. The thermodynamic transition levels within the wide MgO bandgap are estimated for the various charge states. Furthermore, we show that Fe introduces spin polarized 3d levels within the bandgap, with magnetic moments and stabilization energies depending on its charge state.

Main supervisor (name and email)<br>and his / her institution

Prof Nithaya Chetty
Nithaya.Chetty@up.ac.za
University of Pretoria

Level for award<br>&nbsp;(Hons, MSc, <br> &nbsp; PhD)?

N/A