On the Theory of Cyclic Growth Twins

Abstract

Various kinds of crystals are grown by nature in multiply twinned configurations called cyclic twins. Here, for the first time, I will use twinning equations to analyze some representative examples of these. Generally, these can be free of shear stresses only if lattice parameters are somewhat different from those commonly measured at room temperature and atmospheric pressure, and theory provides a description of the former. So, in the usual environment, they must be subject to residual stresses, although they were probably not, in the environment in which they grew.