Hall effect at the metal–nonmetal transition in metal–ammonia solutions

Abstract

The conductivity and Hall coefficient have been measured for solutions of Li, Na, K, and Cs in liquid NH 3 using a double ac method over a concentration range of 1–10 mol% metal (mpm). The conductivities vary from 10 −1 to near 10 4 Ω −1 cm −1 and the Hall coefficients from 10 −6 to 10 −9 m 3 C −1 over the 1–10 mpm range. Hall mobilities vary from 10 −2 to 10 0 cm 2 V −1 s −1 over the same range. The mobility for Na–NH 3 solutions shows a maximum at 4 mpm while the others are monotonie. The mobility peak in Na–NH 3 solutions appears to be related to the presence of substantial composition fluctuations in that system.