Application of nano-polycrystalline diamond to laser-heated diamond anvil cell experiments

Abstract

Laser heating in diamond anvil cell (DAC) equipped with nano-polycrystalline diamond (NPD) anvils was tested for the first time using various types of lasers. An NPD-based DAC was found to provide better heating efficiency than a standard DAC with single-crystal anvils, probably due to the order of magnitude lower thermal conductivity of the NPD. We observed high-temperature generation exceeding 5000 and 3500 K during laser heating of hcp-Fe sample at pressures of ∼100 and ∼170 GPa, respectively. The results of the present study demonstrate promising potential of laser-heated nano-polycrystalline DAC for the generation of very high temperature under multi-megabar pressure conditions equivalent to those of the Earth's core.

Keywords:

• nano-polycrystalline diamond
• diamond anvil cell
• laser heating
• high pressure
• high temperature

Acknowledgements

The authors thank Y. Ohishi and N. Hirao of JASRI and N. Sata of IFREE for their technical assistance in the synchrotron experiments. The synchrotron experiments were conducted at BL10XU of SPring-8 with the approval of JASRI (Proposal Nos 2008B1569 and 2009A1564). This study was supported by a Grant-in-Aid for Young Scientists (B) (#20740255) from the Ministry of Education, Science and Culture, Japan and was also supported partly by a Grant-in-Aid for Specially Promoted Research (#20001005, Representative: T. Irifune) from the Japan Society for the Promotion of Science.