1. Empa. Swiss Federal Laboratories for Materials Science and Technology, Laboratory for High Performance Ceramics, Dübendorf CH-8600, Switzerland
2. Institute for Materials Research (IMO), Hasselt University, Wetenschapspark 1, Diepenbeek B-3590, Belgium
3. IMOMEC, IMEC vzw, Wetenschapspark 1, Diepenbeek B-3590, Belgium
4. Institute for Nuclear Medical Applications, Belgian Nuclear Research Centre, Mol B-2400, Belgium