Systematics of the nonmetal-metal transition in highly compressed low-Z fluids at extreme conditions

Condensed Matter lunchtime seminar

Systematics of the nonmetal-metal transition in highly compressed low-Z fluids at extreme conditions

  • Event time: 1:00pm
  • Event date: 11th March 2003
  • Speaker: B. Nellis (Lawrence Livermore National Laboratory)
  • Location: Room 2511,

Event details

Electrical conductivities have been measured for hydrogen, nitrogen, and oxygen at pressures of 100 to 200 GPa and temperatures of several 1000 K. At these extreme conditions these fluids are highly compressed and degenerate, probably monatomic, and undergo a nonmetal-metal transition. Published conductivity data are also available for fluid Cs and Rb at 2000 K. These alkali fluids undergo a similar transition. In the semiconducting phase the density dependences of all five conductivities differ significantly and are strongly correlated with the radial charge-density distributions of the respective atoms. Metallic conductivities are essentially the same for all five and are the minimum conductivity of a metal, which is weakly sensitive to element. These conductivity data for all five elements in this newly accessible regime are indicative of a Mott transition.

This is a weekly series of informal talks given primarily by members of the soft condensed matter and statistical mechanics groups, but is also open to members of other groups and external visitors. The aim of the series is to promote discussion and learning of various topics at a level suitable to the broad background of the group. Everyone is welcome to attend..

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