1. Otto H. York Department of Chemical, Biological, and Pharmaceutical Engineering, New Jersey Institute of Technology, University Heights, Newark, New Jersey 07102, USA
2. Institute of Materials Physics and Technology, Hamburg University of Technology (TUHH), Eißendorfer Str. 42, D-21073 Hamburg-Harburg, Germany
3. Center for Materials Physics and Technology, Naval Research Laboratory, Washington, DC 20375, USA