Ce-Al compounds display a variety of unconventional magnetic propertie
s at low temperatures. This is particularly well demonstrated by the r
esults of our low-frequency NMR studies on CeAl2, CeAl3 and Ce3Al11. A
lthough CeAl2 orders antiferromagnetically below 3.4 K, the temperatur
e dependence of the spin-lattice relaxation rate follows a Korringa la
w below 1 K. For CeAl3, we observe an increase of the line width below
0.9 K, but no indication of a phase transition is discernible from th
e temperature dependence of the spin-lattice relaxation rate. Ce3Al11
is ferromagnetic below 6.2 K, but develops an antiferromagnetic and mo
dulated structure below 3.3 K. A field of the order of 3 kG, however,
appears to stabilize the ferromagnetic phase. Our spectroscopic data a
re important in view of some of the unusual thermal properties of thes
e materials.