The magnetization curves of U6Fe were measured at several constant tem
peratures by a SQUID magnetometer. The lower critical field H(c1) was
determined on the basis of Bean's model. H(c1) follows a 1-(T/T(C))4 d
ependence and its extrapolated value at T=0 is 92 Gauss. H(c1) is thre
e orders of magnitude smaller than H(c2).