1. Laboratory for High Performance Ceramics, EMPA, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf 8600B, Switzerland
2. Faculty of Materials Science and Ceramics, AGH, University of Science and Technology, Krakow 30-059, Poland
3. Institute of Ceramic, Glass and Construction Materials TU Bergakademie Freiberg, Freiberg 09599, Germany