Modulated phases in Ising models with diluted frustration

A particular class of periodic Ising models with diluted frustration is studied using a simple recursion relation for spinor correlation functions. A modulated phase is found at T = 0 which extends into a modulated paramagnetic phase for finite temperatures. The disorder line at which this latter phase changes into a paramagnetic phase is located. In a study of the ground state excitations of the model contact is made with results known for the ANNNI-model.