sio2 structure

The basic chemical bonds in silicon oxide is Si-O bond (containing 50% and 50% of the covalent bond
ionic bond).
Oxidation of silicon atoms in the basic structure is composed of Si-O bond is tetrahedral, each Si ion
is surrounded by four tetrahedral distribution of O ions (Si and O ion-ion center between the centers
distance of 1.6?, O ions and O ions the distance between the centers of 2.27?). Then, the Si-O
tetrahedral angle of O ions through the rules to connect together to form network-like structure, which
constitutes a crystalline silicon oxide. Otherwise, if the Si-O tetrahedral connections are not very
rules that form a network structure of some confusion, for the amorphous silicon oxide.
Obviously, there are many in the silicon oxide by a number of Si-O tetrahedron made ​​of hollow
surrounded by (the middle of the empty network), these relatively large empty volume. In fact, Si-O
molecule itself occupies the entire volume of the smaller, only 43%, and most of them are empty.
Therefore, a smaller proportion of silica, crystalline silica is 2.65g/cm3, amorphous silicon oxide for
2.21g/cm3. As a result, silica is relatively easy to allow a smaller radius of H, Na, K, Ca, Ba and
other impurity atoms into their network structure (in the hollow inside), and these hetero-atom
diffusion in the network structure also more easily, often referred to as the network changes this
impurity agent.
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Nanometer SiO2