Axial Ising model with third-neighbour interactions

A three-dimensional Ising model with competing interactions up to third-neighbour layers is analysed using low-temperature series expansions and mean field theory. New sequences of phases springing from multiphase lines are found and the crossover to the behaviour of the ANNNI model is studied. Results are related to experimental findings on alloys, ferroelectrics, and polytypes. © 1985 The Institute of Physics.