3-7 July 2017
Africa/Johannesburg timezone

Density functional based tight binding (DFTB+) studies of pentlandites (Fe, Co, Ni)<sub>9</sub>S<sub>8</sub> minerals

7 Jul 2017, 10:20
20m
A403A (Engineering Building 51)

A403A

Engineering Building 51

Oral Presentation Track A - Division for Physics of Condensed Matter and Materials Physics of Condensed Matter and Materials 1

Speaker

Dr Thabo Letsoalo (University of Limpopo)

Description

Density functional based tight-binding method (DFTB+) is code which can calculate the small atoms electronic properties and molecular dynamics of large structures. We used parameterization techniques to study pentlandite minerals and large structure using a density functional based tight-binding (DFTB+) method. Pentlandite structures are the transitional-metal sulfides of the Fe, Ni group elements, and Co9S8being the only known binary phase. We developed sets of parameters for Co9S8, Fe9S8, Ni 9S8, and Fe4Ni5S8mineral compounds. However Co-S, Fe-S, Ni-S and S-S interaction pairs produced a good bond lengths and the lattice parameters of these pentlandites minerals sulfides gave a good agreement of DFT-based calculations and experimental results. We calculated molecular dynamics on (1 1 1) surface Co9S8 nanoparticle from 300K to 1000K, and showed a zero band gap at a higher temperature. Supercell of pentlandite structure Fe4Ni5S8 with 1864 atoms, the density of states (DOS) showed a band gap structure with a zero Fermi energy. We alloyed supercell of pentlandite structure Fe4Ni5S8 of 1864 atoms with oxygen and changed the electronic properties with significance importance properties of pentlandites minerals.

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

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

N/A

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

Prof Phuti Ngoepe
Phuti.Ngoepe@ul.ac.za
University of Limpopo

Primary author

Dr Thabo Letsoalo (University of Limpopo)

Co-author

Prof. Phuti Ngoepe (University of Limpopo)

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