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Abstract

The electrical resistance of a single crystal of PuTe has been measured up to almost 25 Gpa and as a function of temperature down to 1.3 K. At low pressure, the resistance R displays the expected activated behaviour ie an up-turn at low-temperature and a change of curvature at almost 200 K as at ambient pressure. Surprisingly, the resistance at 1.5 K is enhanced with pressure. For the NaCl phase, we propose a model where the conductivity omega is composed of three contributions: a constant 0 K-term as expected in a semimetal, the Mott's law indicating variable range hopping conductivity between 100 K and an exponential term due to a band gap. At 0.2 Gpa, the activation energies T0 and Eg equal 23 meV and 0.185 eV, and increase up to 110 meV and almost 0.4 eV at 4.2 Gpa respectively. As a possible origin of the Mott's law, we suggest the mechanism of hopping conduction between the 5f localized states of the Pu ions.

Between 10.7 Gpa and 12.7 Gpa, R strongly decreases over the whole temperature range. We attribute this collapse to the NaCl-CsCl structural transition. This effect indicates a strong increase of the state density and is in agreement with theoretical predictions. Above 12.7 Gpa, the up-turn tends to disappear and the temperature variation of R progressively approaches that of a metal. Our data suggests a magnetic transistion below 15 K in the CsCl phase. .

Additional information

Authors: ICHAS V, European Commission, Joint Research Centre, Institute for Transuranium Elements, Karlsruhe (DE);GRIVEAU J C, European Commission, Joint Research Centre, Institute for Transuranium Elements, Karlsruhe (DE);REBIZANT J, European Commission, Joint Research Centre, Institute for Transuranium Elements, Karlsruhe (DE);SPIRLET J C, European Commission, Joint Research Centre, Institute for Transuranium Elements, Karlsruhe (DE)
Bibliographic Reference: Article: Physical Review of Condensed Matter, further details unknown
Availability: Physical Review of Condensed Matter (journal)
Record Number: 200012315 / Last updated on: 2000-09-20
Category: PUBLICATION
Original language: en
Available languages: en