Heavy-fermion behavior in CeAl2 nanoparticles

In order to examine the quantum size effects on the heavy-fermion behavior in CeAl2, we have performed measurements of the low-temperature specific he ats for CeAl2 nanoparticles with average particle size 80 Angstrom for temp erature down to 80mK. For 80 Angstrom - nanoparticles the magnitude of gamm a of CeAl2 can be as high as 3600mJ/K-2 f.u. at T=80mK with TK approximate to 0.65K. Compared with the sharp anti-ferromagnetic order (T-N=3.8K) in bu lk CeAl2 only a blurred peak at same temperatures is observed in CeAl2 nano particles. Due to the suppression of the long-range magnetic order by the l imited geometric size and the less degeneracy of the density of states of c onduction electrons D(epsilon(F)) the enhanced heavy-fermion behavior (in t erms of gamma) and the disappearance of magnetic order in CeAl2 nanoparticl es are attributed to the quantum size effects in nanoparticles. (C)1999 Act a Metallurgica Inc.