1. Instituto de Fisica, Universidade Federal do Rio de Janeiro, 21941-972 Rio de Janeiro, RJ, Brazil
2. Instituto Nacional de Metrologia Qualidade e Tecnologia, 25250-020 Duque de Caxias, RJ, Brazil
3. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
4. School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
5. Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China