1. Ceramics Laboratory; EPFL - Swiss Federal Institute of Technology; Lausanne 1015 Switzerland
2. Department of Materials Science and Engineering; Norwegian University of Science and Technology; Trondheim 7491 Norway
3. Grupo de Cerâmicas Ferroelétricas - GCFerr; Departamento de Física; Universidade Federal de São Carlos; São Carlos CEP 13565-670 São Paulo Brazil