Decreasing electrical resistivity of silver along the melting boundary up to 5 GPa

ABSTRACT

The electrical resistivity of Ag was experimentally measured at high pressures up to 5 GPa and at temperatures up to ∼300 K above melting. The resistivity decreased as a function of pressure and increased as a function of temperature as expected and is in very good agreement with 1 atm data. Observed melting temperatures at high pressures also agree well with previous experimental and theoretical studies. The main finding of this study is that resistivity of Ag decreases along the pressure- and temperature-dependent melting boundary, in conflict with prediction of resistivity invariance. This result is discussed in terms of the dominant contribution of the increasing energy separation between the Fermi level and 4d-band as a function of pressure. Calculated from the resistivity using the Wiedemann–Franz law, the electronic thermal conductivity increased as a function of pressure and decreased as a function of temperature as expected. The decrease in the high pressure thermal conductivity in the liquid phase as a function of temperature contrasts with the behavior of the 1 atm data.

KEYWORDS:

• Silver
• electrical resistivity
• thermal conductivity
• high pressure temperature

Acknowledgements

We thank Jonathan Jacobs for help with machining of experimental components.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Natural Sciences and Engineering Research Council of Canada [grant number 105604-2013] and the Canada Foundation for Innovation [project number 11860].