[1] Seoul Natl Univ, Natl Creat Res Initiat Ctr Oxide Nanocrystalline, Seoul 151744, South Korea
[2] Seoul Natl Univ, Sch Chem & Biol Engn, Seoul 151744, South Korea
[3] Cornell Univ, Depart Chem & Chem Biol, Ithaca, NY 14853 USA
[4] Seoul Natl Univ, Dept Phys & Astron, Seoul 151744, South Korea
[5] Seoul Natl Univ, Interface Control Lab, Seoul 151744, South Korea
[6] Seoul Natl Univ, Sch Mat Sci & Engn, Seoul 151744, South Korea
[7] Cornell Univ, CHESS, Ithaca, NY 14853 USA
[8] Cornell Univ, Wilson Lab, Ithaca, NY 14853 USA