Atomistic simulation studies of zircon

Computer simulation techniques, based on energy minimization procedures, have been applied to investigate the structural properties of zircon (ZrSiO4). A potential model has been derived which can reproduce the crystal structure, having good agreement between calculated and experimental data. Defect energies are calculated to predict the most favourable site for a dopant ion to be occupied in the host lattice. The solution energies are calculated for mono, di, tri, tetra and pentavalent cations. These calculations suggest that all cations, except Al, prefer to substitute at the Zr sites; whereas Al substitutes at the Si sites. These results show that ionic radii of the host and dopant play a vital role for site determination, For pentavalent cations it is energetically more favourable to convert into tetravalent state and then substitute at the Zr sites. (C) 2001 Elsevier Science B.V. All rights reserved.