**Acknowledgements**

The authors would like to thank Prof. Hikari Fujii and Mr. Hiroyuki Kosukegawa of Akita University for the helpful discussion and support during TRT measurements. Also, the authors wish to extend special thanks to Prof. Punya Charusiri, Dr. Srilert Chotpantarat, Ms. Sasimook Chokchai of Chulalongkorn University, Thailand, and also Mr. Trong Thang Tran of Vietnam Institute of Geoscience and Mineral Resources, Vietnam, for their valuable support in this research.

This research is partially supported by:

