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Electron irradiation induced phase decomposition in an alkaline earth multi-component oxide glass has been observed in a scanning transmission electron microscope. Separate regions that are rich and poor in alkaline earths form rapidly during the initial irradiation. In other words, alkaline earth multi-component oxide glasses are intolerant of high-energy (∼ 100 kV) electrons. This could result from the characteristics of a nonbridging O atom that bound to both Si (covalent) and alkaline earths (ionic). A modified Knotek-Feibelman model has been introduced to interpret the breakaway of cations from the glass network. Driven by electrostatic forces, the cations prefer to segregate, forming a cation rich region to reduce the amount of nonbridging O. [ABSTRACT FROM AUTHOR]

In this letter, we report precipitation of nanometer scale Zn crystalline particles in Zn borosilicate glass induced by 100 keV electron irradiation. Nanometer Zn crystalline particles precipitate rapidly in the glass under high intensity electron irradiation. A double ionization mechanism is proposed in interpretation of the formation of Zn particles. Thermal effects are less important than ionization interactions. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]