Two-Dimensional Representations of Defect Concentrations

Equation (13) is basically a four-dimensional representation (under a fixed total pressure) of defect structure, that is not easy to visualize with ordinary vision. The normal practice is, thus, to represent in two dimensions log [S] versus log 0x102 ( fixed 002 and T), log [S versus log Ooj (at fixed OxiOj and T), or log [S] versus 1/T(at fixed 0xi02 and O02). 

To make the situation simpler, it can be assumed that the initial batch composition, whether doped or not, is with aTi02-deficit (q 0) such that  

Each defect concentration in Eq. (3) can then be transformed, by replacing OxiOz with Eq. (27), into a form 

let us suppose that the fixed nonmolecularity is such that 

Finally, there may be interest in the variation of axiOj with Ooj while T is held fixed. This can be calculated via Eq. (27) or Eq. (6), or more easily in the present case, as 

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