J. Phys. IV France 128 (2005) 41-44
Environmentally safe synthesis of SrBi2Ta2O9 and SrBi2Nb2O9 thin filmsG. González-Aguilar, M. Elisabete, V. Costa and I.M. Miranda Salvado
Departamento de Engenharia Cerâmica e do Vidro and CICECO, Universidade de Aveiro, Campus de Santiago, Aveiro 3810-193, Portugal
The modern industry of electronic devices has driven the development of new synthesis methods for producing materials with the desired properties. Most of these methods rely on reagents and solvents that are toxic for human health and environment. For example, it has been reported that the preparation of thin films by metallorganic deposition methods (MOD) often requires noxious chemicals. SrBi2Ta2O9 (SBT) and SrBi2Nb2O9 (SBN) are ferroelectric compounds with important applications as non volatile ferroelectric random access memories (NVFRAM). The advantage of being lead-free compounds is partially loss if the necessary efforts for making their precursors synthesis as safe as possible are not made. In this work a new method using an ethanol-based solution and starting from the acetates of the desired cations for obtaining SBT and SBN thin films is described. The properties of the obtained films demonstrate the good quality of the so prepared materials: the remnant polarization (Pr) values are around 6 C/cm2 and 10 C/cm2 for stoichiometric SBT and SBN respectively, and the observed leakage currents stay below 3A for applied fields of 240 kV/cm2. These characteristics indicate the present method to be adequate for producing ferroelectric materials with suitable properties for memories applications.
© EDP Sciences 2005