Exploiting optical properties of nanopolycrystalline diamond in high pressure experiments

ABSTRACT

We investigated the optical properties (absorption, luminescence and Raman spectra) of nanopolycrystalline diamond (NPD) aiming at exploring its capabilities as a pressure sensor and as a pressure-cell anvil for combined X-ray/neutron and optical studies. Notably, we analysed the Raman peak shift and broadening with pressure using a Moissanite Anvil Cell (MAC). The results are compared with those obtained in a DAC, where Raman signals from NPD chips and diamond anvils strongly overlap. Its pressure behaviour in the hydrostatic and non-hydrostatic regimes were investigated. We showed that the nanopolycrystalline structure induces remarkable differences in the peak shift and broadening between NPD and natural type IIa single-crystal diamond, making NPD suitable as pressure gauge for pressure determination and testing hydrostaticity of pressure transmitting medium.

KEYWORDS:

• Raman spectroscopy
• luminescence
• pressure gauge
• pressure sensitivity
• nanopolycrystalline diamond

Acknowledgements

We acknowledge the PRIUS Collaborative Project (2013–2018) through which we obtained suitable NPD samples.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Financial support from Projects MAT2015-69508-P; PGC2018-101464-B-I00 and MALTA -Consolider Team RED2018-102612-T (Ministerio de Ciencia, Innovación y Universidades) is acknowledged.