1Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
2Pentax New Ceramics Division, Hoya Corporation Tokyo 174-8639 (Japan)
3Autonomic Materials Systems Group Beckman Institute for Advanced Science and Technology University of Illinois at Urbana-Champaign Urbana, IL 61801 (USA)
4School of Advanced Materials Engineering, Kookmin University, Seoul, 136-702, Korea
5Department of Materials Science and Engineering Northwestern University Evanston, IL 60208 (USA)