Cation coordination in oxychloride glasses

Abstract

Glasses containing mixtures of cations and anions of nominal compositions [Sb 2 O 3 ] x -[ZnCl 2 ] 1−x where x = 0.25, 0.50, 0.75, and 1.00, have been studied by means of neutron diffraction and Raman and Mössbauer spectroscopy. There is preferential bonding within the system with the absence of Sb-Cl bonds. Antimony is found to be threefold coordinated to oxygen, and zinc fourfold coordinated. The main contributing species are of the form [Sb(OSb) 2 (OZn)] and [Zn(ClZn) 2 (OSb) 2 ].

Solid-state chemistry of glassy antimony oxides

“…as demonstrated by Debenedetti and co-workers. 39,40 However, the contracted tetrahedral bonding angle observed in the antimony oxides (921 from the work of Johnson et al, 41 and 95.61 in our simulations) imposes a technical limitation in distinguishing tetrahedral and octahedral motifs in a manner similar to e.g. ref.…”

Structure of oxychloride glasses by neutron and x-ray difference and x-ray photoelectron spectroscopy

“…The compositions are given in atomic% in order to allow comparison of the losses occurring during melting. X-ray diffraction confirmed the glassy nature of the samples and 121 Sb Mössbauer spectroscopy confirmed that antimony was present in the trivalent Sb 3+ state only [1].…”

“…This makes the task of assigning peaks a simpler job. The distinguishable peaks were fitted with deconvoluted Gaussians (representative fits have been previously shown [1]) from which the peak positions and co-ordination numbers are derived. These are summarized in table 3.…”

“…Glass preparation details have been reported elsewhere [1]. X-ray diffraction was used to check the amorphicity of the glasses and density was determined using an autopycnometer.…”

“…However, such glasses are of significant technical importance; oxynitrides represent the residual glass phase in engineering ceramics and mixed chalcogenide glasses and oxyhalide glasses are of relevance to optical applications. We have performed earlier studies on oxychloride glasses developed for IR transmission and as low phonon energy hosts for lasing ions [2,3], and recently we have reported the results of a neutron diffraction study of the Sb 2 O 3 -ZnCl 2 system which indicated that preferential cation-anion associations do occur [1]. The interpretation of the neutron diffraction data required various assumptions to be made about coordination number because of the overlap of the metal-oxygen correlations and also overlap of the metal-chlorine 5 Author to whom any correspondence should be addressed.…”