1. Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
2. Fuel Cell Laboratory, Korea Institute of Energy Research, Daejeon 34129, Republic of Korea
3. Division of Advanced Materials Science, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
4. European Synchrotron Radiation Facility, 71, Avenue des Martyrs, Grenoble 38043, Cedex 9, France
5. Pohang Accelerator Laboratory, Pohang University of Science and Technology, Pohang 37673 Republic of Korea