Electrons on the threshold of localization

This thesis deals with a series of liquid alloy systems exhibiting gradually increasing deviations from simple metallic behaviour: Li-Na, Li-Mg, Li-Cd, Li-In, Li-Sn, Li-Pb, Na-Sn and Na-Se. In chapter 2 those parts of the theory on electronic and thermodynamical properties of liquid metals which are used are summarized. In chapter 3 details are given on the equipment and the experimental techniques. Thermopower measurements on liquid Li-Na alloys, and more particular the critical effects observed in this quantity close to the top of the immiscibility curve, are reported in chapter 4. Measurements of the Knight shift of pure liquid lithium at temperatures between 180 0C and 720 0C are reported in chapter 5. Chapter 6 describes the 7Li Knight shift measurements on liquid Li-Mg alloys. The chapters 7, 8 and 9 are concerned with measurements (a.o. electrical resistivity and Knight shift) on liquid Li-Cd, Li-In, Li-Sn and Li-Pb alloys. Measurements of the electrical resistivity of liquid Na-Sn alloys have been carried out consecutive to those on liquid Li-Sn alloys, in order to observe the effect of the difference in atomic volume of Li and Na; this difference amounts to a factor of nearly two. The measurements on liquid Na-Sn are reported and discussed in chapter 10. Measurements of the electrical resistivity of selenium-rich liquid Na-Se alloys are presented in chapter 11. In this case the metal-nonmetal (MNM) transition is approached (but not attained in the reported measurements) from the other side. Some general conclusions are drawn in chapter 12. (Auth.)