Influence of nonstoichiometry on ferroelectric phase transition in BaTiO(sub)3

The study focuses on transition temperature variations as a function of Ba/Ti ratio and in undoped BaTiO(sub)3 powders with particle size to understand stoichiometric effects on transition behavior when materials are processed under equilibrium conditions, before introducing additional degrees of freedom such a dopants, size effect or applied stress. It is found that all the different defects contribute to the changes of transition temperature and enthalpy of transition.