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How do network formers and network modifiers affect oxide glass structure?

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In the study of amorphous solids, oxide glass structure is defined by the interaction between network formers and network modifiers.

Network Formers

Network formers are chemical species that create the structural backbone of the glass. They form strong chemical bonds with oxygen atoms to establish a continuous, disordered network. Common examples include:
* Silica (SiO₂): The prototypical glass former, where each silicon atom bonds to four oxygen atoms.
* Other oxides: Oxides of boron (B³⁺), germanium (Ge⁴⁺), and phosphorus (P⁵⁺) also function as network formers.

Network Modifiers

Network modifiers are chemical species that do not bond directly into the structural network. Instead, they exist in ionic form within the interstitial holes of the network. These agents, such as sodium (Na⁺) and calcium (Ca²⁺), significantly alter the physical properties of the glass. For instance, adding modifiers like soda (Na₂O) acts as a flux, reducing the viscosity and melting temperature of the glass, while stabilizing oxides like lime (CaO) and magnesia (MgO) improve chemical durability.