Structure and triclustering in Ba-Al-O glass

L B Skinner, A C Barnes, Philip S Salmon, H E Fischer, James W E Drewitt, V Honkimäki

Research output: Contribution to journalArticle

32 Citations (Scopus)
178 Downloads (Pure)

Abstract

Glass-forming ability in the (BaO) x(Al 2O 3) 1-x system (0≤x≤1) was investigated by using the containerless aerodynamic levitation and laser-heating method. The main glass-forming region was found to occur for 0.40(2) ≤x≤ 0.48(2), where there is insufficient oxygen to form an ideal network of corner-sharing AlO 4 tetrahedra in which the oxygen atoms are twofold coordinated, with another narrow glass-forming region at x = 0.62(2) around the eutectic composition. The glass corresponding to x = 0.4 was chosen for further investigation by using both neutron and x-ray diffraction, and a detailed atomistic model was built by applying a combination of molecular dynamics and reverse Monte Carlo methods. The results show a network structure based predominantly on corner-sharing tetrahedral AlO 4 motifs in which triclusters (OAl 3 units formed by three tetrahedral Al atoms sharing a common vertex) play an integral part, with as many as 21% of the oxygen atoms involved in these configurations. The barium ions bind to an average of 7.4 O atoms, most of which are twofold-coordinated bridging oxygen atoms. The larger size of barium compared to calcium narrows the range of glass-forming compositions in alkaline-earth aluminates such that the main glass-forming range corresponds to a regime in which an oxygen-deficient Al-O network is stabilized by the formation of triclusters.
Original languageEnglish
Article number064201
JournalPhysical Review B
Volume85
Issue number6
DOIs
Publication statusPublished - 22 Feb 2012

Fingerprint Dive into the research topics of 'Structure and triclustering in Ba-Al-O glass'. Together they form a unique fingerprint.

  • Projects

  • Equipment

  • Cite this

    Skinner, L. B., Barnes, A. C., Salmon, P. S., Fischer, H. E., Drewitt, J. W. E., & Honkimäki, V. (2012). Structure and triclustering in Ba-Al-O glass. Physical Review B, 85(6), [064201]. https://doi.org/10.1103/PhysRevB.85.064201