Transverse Spin Diffusion in 3He-4He Mixtures-Part I

There is currently a debate on whether or not the transverse relaxation time is finite at low temperature in spin-polarized Fermi liquids. The experimental results so far have been contradictory. In this paper, the first in a series of two articles, we present NMR measurements carried out in 6.2% 3He-4He mixture at 11.3 T down to 3.5 mK. A careful analysis of our data yields an anisotropy temperature T a = 6.1±1 mK, which is smaller than the values reported previously. The difference between this value and the earlier results is ascribed to restricted diffusion effects which were neglected in the previous analyses. The details of the analysis are given in the companion paper.