AL-27 NUCLEAR-MAGNETIC-RESONANCE SPECTRA IN CEAL3 AT LOW-TEMPERATURES

We have measured the nuclear magnetic resonance, NMR, spectra of CeAl3 at 3.964 MHz, 2.095 MHz and 0.937 MHz in the temperature range betwee n 0.04 K and 20 K. The complicated NMR absorption line of CeAl3 powder is shown to have more than one component, corresponding to at least t wo inequivalent Al sites. Below 0.9 K the relative intensity of a broa d asymmetric structure increases, and the width of the NMR spectrum sh ows a rapid increase. At fields of the order of two kilogauss the asym metry is strongly supressed. The temperature dependence of the asymmet ry and width of the spectrum below 0.9 K, can neither be explained in terms of a temperature dependent Knight shift nor in terms of conventi onal magnetic ordering.