We have investigated the complex ac conductivity of La1-xSrxMnO3 for 0 less
than or equal to x less than or equal to 0.2, temperatures 15 K less than
or equal to T less than or equal to 300 K and frequencies 20 Hz less than o
r equal to nu less than or equal to 1.8 GHz. In addition, results from de m
easurements are presented. From the frequency dependence of the complex con
ductivity we find hopping of Anderson-localized charge carriers as the domi
nant transport process in certain temperature and composition ranges. We de
duce that, while Anderson localization is not the driving mechanism for the
metal-insulator transition observed in this compound, it is responsible fo
r the high-resistivity regions observed at low doping levels and low temper
atures. The results indicate a polaronic nature of the charge carriers. Fro
m the temperature dependence of the ac conductivity and the magnetic permea
bility, deduced in the skin-effect-dominate regime, various phase transitio
n temperatures have been determined.