The de Haas-van Alphen (dHvA) effect is used to study angular-dependent ext
remal areas of the Fermi surfaces and effective masses of CexLa1-xB6 alloys
for x between 0 and 0.05. The dHvA signals from these alloys are observed
to change from that arising from the normal two-spin metal, LaB6, to a sing
le-spin sheet signal at x = 0.05.