Properties of Some High Al Content Glasses in Various Lanthanide‐Si—Al—O—N Systems

Abstract

Inorganic chemistryInorganic chemistry Z 0100 Properties of Some High Al Content Glasses in Various Lanthanide--Si-Al-O-N Systems-[25 refs.]. -(REDINGTON, W.; REDINGTON, M.; HAMPSHIRE, S.; SERANTONI, M.; J. Non-Cryst. Solids 316 (2003) 1, 74-81; Dep. Mater. Sci. Technol., Univ. Limerick, Limerick, Ire.; Eng.) -Schramke 23-219

Composition–structure–property relationships of transparent Ca–Al–Si–O–N oxynitride glasses: The roles of nitrogen and aluminum

“…Poisson's ratio relates to the rigidity of the glass network and its dimensionality, where a higher (lower) ν value normally correlates with a lower (higher) network connectivity/rigidity 56,72 . Yet, oxynitride glasses generally exhibit higher Poisson's ratios than their N‐free aluminosilicate‐based counterparts 30,44,99,103 . The present Ca–Al–Si–O–N glasses reveal a narrow span of Poisson's ratios between 0.260 and to 0.278 for the I‐3.2 and II‐7.2 glass specimens, respectively (Table 2).…”

“…56,72 Yet, oxynitride glasses generally exhibit higher Poisson's ratios than their N-free aluminosilicate-based counterparts. 30,44,99,103 The present Ca-Al-Si-O-N glasses reveal a narrow span of Poisson's ratios between 0.260 and to 0.278 for the I-3.2 and II-7.2 glass specimens, respectively (Table 2). The minute variations of the Poisson's ratio did not suggest any clearly identifiable trend against n N or any other glass constituent.…”

“…Indeed, the hardness of oxide/oxynitride M-Al-Si-O-(N) glasses indeed increase concurrently with the M z+ cation field strength (CFS). 3,4,22,30,99 More recently, however, another explanation for the enhanced hardness of RE-based M-Al-Si-O glasses was proposed, 23,83,100 which is argued to most likely also hold for their oxynitride counterparts. 100 Despite originating from the M z+ CFS, it is not the (potentially enhanced) network cross-linking from the M-O-Si/Al bond fragments themselves that boost the mechanical glass properties, but merely the presence of high-coordination Al [5] /Al [6] populations of the aluminosilicate network induced by the high-CFS network-modifier cations.…”

La-Si-O-N glasses

“…The values have been found to vary linearly with N content, density of the glass and ionic radius of rare-earth (RE) glass modifier/dopant, with the effects of N and RE contents being independent and additive. 6,7 Studies of compositional dependencies of hardness are predominant for glasses containing, in addition to Si, Y and Al, 1,2,[8][9][10][11][12] and RE and Al, 5,[13][14][15] with the latter mainly concerning variations with the ionic radius and/or cationic strength * Corresponding author. Tel.…”

“…Glass forming regions and properties of oxy-nitride glasses [1][2][3][4][5] have been studied chiefly because they occur as grain-boundary phases in silicon nitride ceramics, in which the composition and volume fraction of them determine the properties of the materials, particularly the high-temperature mechanical properties. The studies have shown that a number of physical and mechanical property values, including hardness, fracture toughness, elastic modulus and refractive index, increase with increasing nitrogen content.…”