a1 Commission of The European Communities, Joint Research Center, Institute for Advanced Materials, Ispra-21020, Italy
a2 Commission of The European Communities, Joint Research Center, Institute for Transuranium Elements, Karlsruhe 7500, Federal Republic of Germany
We present an investigation of the influence of four dopant lithium concentrations on the electrical properties of CuO. X-ray measurements have revealed a single phase formed up to 4.2 at. % of Li, and a second phase formed, Li2CuO2, in the case of 10.5 at. % of Li concentration. The log(ρ/T) vs 1/T data are better represented by two straight lines than by one and show an initial strong decrease of the conduction activation energies for small contents of Li (<1.7 at. %), which becomes weak for larger contents. The change in slope observed in the resistivity measurements as a function of temperature has also been investigated by calorimetric measurements, revealing a specific heat anomaly which can be associated with the antiferromagnetic order transition.
(Received February 08 1990)
(Accepted April 10 1990)