1. State Key Laboratory of Crystal Materials Shandong University Jinan 250100 China
2. Department of Materials and Environmental Chemistry Arrhenius Laboratory Stockholm University Stockholm SE‐106 91 Sweden
3. Department of Physics Stockholm University Stockholm SE‐106 91 Sweden
4. Department of Chemical Engineering KTH Royal Institute of Technology Stockholm SE‐100 44 Sweden
5. Department of Materials Science and Engineering Ångström Laboratory Uppsala University Uppsala SE‐751 03 Sweden