In magnetic low carrier density systems, in addition to the strong int
ra-atomic correlation, a strong correlation due to the long-range Coul
omb interaction becomes important, causing a tendency to Wigner crysta
l or liquid system. In magnetic systems, the tendency to localization
is further enhanced by magnetic polarization, and the magnetic polaron
liquid and lattice are fairly easily formed. This is most clearly see
n in CeP and CeAs; a detailed description is given in this paper. A we
ak Gamma(8) hole magnetic polaron is formed in a liquid state even at
room temperature. The population of the magnetic polaron decreases wit
h decreasing population of 4f Gamma(8) but persists even at the lowest
temperatures. An applied field and pressure change the weak magnetic
polaron liquid to a strong magnetic polaron lattice with nearly satura
ted moment.