As Mitchell 1 said in 1954 “With the discovery of each new polymorph of silicon carbide, it becomes more evident that there is no limit to the possible modifications of this substance…” An intriquing question however still remains “When does a long period polytype (LPP) become a one-dimensionally disordered (1DD) layer ?”
In attempting to answer this question, nearly 50 years later Kelly 2 et al. believe they have found the answer in an equation. Is it possible that such a simple expression as t = k N - n can not only herald the onset of the transition from an ordered, albeit long period structure to disorder but also a limit to the number of possible polytypes in nature ?
To find out more: doi:10.1016/j.materresbull.2004.10.008
References:
1. Mitchell R.S. (1954) J. Chem. Phys. 22, 1977-1983.
2. Kelly J.F., Fisher G.R. and Barnes P (2005) Mat. Res. Bull. 40, 249-255.
