Break junctions of the heavy-fermion antiferromagnet CeAl2

Mechanical-controllable break junctions of CeAl2 were investigated down to 50 mK. The size of the contacts turns out to be the most important parameter. We analyze the junctions by applying Wexler's resistance formula, and derive the contact radius by comparing the T-3 - power law of the zero-bias resistance below T-N with that of the electrical resistivity. On the average the local residual resistivity rho(0) approximate to 15 mu Omega cm amounts to about 5 times the bulk value, while the effective Fermi wave number k(F) approximate to 2 nm(-1) is considerably smaller than expected.