M. Huijben,1,2,* L. W. Martin,1 Y.-H. Chu,1,3 M. B. Holcomb,1 P. Yu,1 G. Rijnders,2 D. H. A. Blank,2 and R. Ramesh1 1Department of Materials Science and Engineering and Department of Physics, University of California, Berkeley, California 94720, USA and Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA 2Faculty of Science and Technology and MESA Institute for Nanotechnology, University of Twente, P.O. BOX 217, 7500 AE Enschede, The Netherlands 3Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan Received 2 July 2008; revised manuscript received 31 July 2008; published 16 September 2008