Orderedisorder phase transitions in thin films described by transverse Ising model

Abstract

The order-disorder phase transition in thin films at finite temperature and zero temperature (quantum phase transition) is discussed within the transverse Ising model using molecular field approximation. Experimentally, it is shown that the Curie temperature TC of perovskite PbTiO3 ultra-thin film decreases with decreasing film thickness. We obtain an equation for TC of thin film in external magnetic and transverse fields. Our equation explains well for the case of strong transverse strain field this behaviour.