Kroger-Vink Notation for Donor Doping

[dadon]

Hi All..

I'm having some trouble trying to understand the Kroger-Vink notation.. the following example is of donor doping (for semi conductor, extrinsic)..

the first equation is meant to be elecronic compenstaion while the bottom equation is ionic compensation

 

[Mapes]

The key with K-V notation is to simultaneously balance matter, charge, and sites. I believe the notation arose as a way to save space by tilting the typewriter platen and typing one or multiple periods, apostrophes, or xs. Why they couldn't just use the conventional, for example, "3-" or "4+" for charge I don't know.