High X2 Partial Pressures Electronic Defects

At ever higher partial pressures the number of nonmetal vacancies will diminish more and more and the number of holes will exceed the number of vacancies in this regime. Thus the approximate electroneutrahty Eq. (7.13) will no longer be representative. A more appropriate form of the electroneutrality equation for the high-pressure region is obtained by ignoring the minority species, nonmetal vacancies and electrons, to give 

This can now be substituted into Eqs. (7.7)-(7.10) to obtain relationships between the partial pressure of X2 and the defect concentrations present in the material relevant 

---