Critical phase transition temperatures of 1-3 type multiferroic composite thin films

The critical phase transition temperatures of the ferroelectric (FE) phase and the ferromagnetic (FM) phase in epitaxial 1 - 3 type multiferroic thin films were obtained based on the thermodynamic model. Analytic expressions of the para - ferro transition temperatures were derived as functions of the volume fraction of the FM phase by considering the effect of the coupled elastic stresses arising from the FE/FM and the film/substrate interfaces. Our results show that the critical temperatures are significantly affected by the induced stresses and can be controlled by adjusting the volume fractions of the different phases within the thin film.