Preparation of iron sesquioxide glasses by ultra-fast quenching from the melt (?splat-cooling?)

Structural studies of lead aluminate glasses

“…Although previous workers [1,4] have reported a high lead limit to the glass forming range of 95 mol% PbO, we could not make a good bulk glass beyond 80.0 mol% PbO without crystallization. Kantor et al [1] do not give details of the method for glass melting, but Morikawa et al [4] state that the glasses were held at melt temperature for only a few seconds, reducing the problem of volatilization. To achieve this, the samples were melted in a small platinum crucible of volume 20 mm 3 .…”

“…This range is much more restricted than has previously been reported in the literature [1,4]. Neutron diffraction and 27 Al MAS NMR studies show that the aluminium in lead aluminate glass is tetrahedrally coordinated, whilst the lead is three coordinated in an asymmetric trigonal pyramid arrangement.…”

“…Further work was carried out by Morikawa et al [4] who used differential thermal analysis (DTA), X-ray diffraction (XRD) and infra-red (IR) spectroscopy to confirm glass formation, and dark field microscopy to identify the presence of minute crystallites. Kantor et al [1] report the glass forming range to be 50-95 mol% PbO, whilst Morikawa et al [4] found the same upper limit, but a different lower limit of 67 mol% PbO. The high PbO contents which have been reported indicate that lead is not acting purely as a modifier in these glasses.…”

“…It was first reported that the system was glass forming, over a significant range in composition, by Kantor et al [1] who used the 'gun technique' for fast cooling of the melts [2]. It was noted that the formation of these glasses was assisted by the presence of a eutectic point at $85 mol% PbO [3], which lowers the melting temperatures required and therefore reduces the problem of lead volatilization.…”

Vibrational and EPR spectroscopic investigation of heavy‐metal‐oxide glasses and vitroceramics containing manganese

“…11 -13 However, in the last years, glasses in which PbO was the main glass former, sometimes besides Bi 2 O 3 (Refs 7, 13), have been successfully synthesised. 14,15 The investigation of binary bismuthate systems such as Bi 2 O 3 -PbO is therefore of great interest for understanding the aforementioned multicomponent systems.…”