A molecular dynamics model of the atomic structure of dysprosium alumino-phosphate glass

Richard A. Martin, Gavin Mountjoy, Robert J. Newport

Research output: Contribution to journalArticle

Abstract

Molecular dynamics (MD) has been used to identify the relative distribution of dysprosium in the phosphate glass DyAl0.30P3.05O9.62. The MD model has been compared directly with experimental data obtained from neutron diffraction to enable a detailed comparison beyond the total structure factor level. The MD simulation gives Dy ... Dy correlations at 3.80(5) and 6.40(5) angstrom with relative coordination numbers of 0.8(1) and 7.3(5), thus providing evidence of minority rare-earth clustering within these glasses. The nearest neighbour Dy-O peak occurs at 2.30 angstrom with each Dy atom having on average 5.8 nearest neighbour oxygen atoms. The MD simulation is consistent with the phosphate network model based on interlinked PO4 tetrahedra where the addition of network modifiers Dy3+ depolymerizes the phosphate network through the breakage of P-(O)-P bonds whilst leaving the tetrahedral units intact. The role of aluminium within the network has been taken into explicit account, and A1 is found to be predominantly (78 tetrahedrally coordinated. In fact all four A1 bonds are found to be to P (via an oxygen atom) with negligible amounts of Al-O-Dy bonds present. This provides an important insight into the role of Al additives in improving the mechanical properties of these glasses.
Original languageEnglish
Article number075102
JournalJournal of Physics: Condensed Matter
Volume21
Issue number7
DOIs
Publication statusPublished - 13 Jan 2009

Fingerprint Dive into the research topics of 'A molecular dynamics model of the atomic structure of dysprosium alumino-phosphate glass'. Together they form a unique fingerprint.

  • Cite this