Magnetization and spin diffusion of liquid He 3 in aerogel

We report theoretical calculations and experimental measurements of the normal-state spin diffusion coefficient of $^{3}\mathrm{He}$ in aerogel, including both elastic and inelastic scattering of $^{3}\mathrm{He}$ quasiparticles, and compare these results with data for $^{3}\mathrm{He}$ in 98% porous silica aerogel. This analysis provides a determination of the elastic mean free path within the aerogel. Measurements of the magnetization of the superfluid phase in the same aerogel samples provide a test of the theory of pairbreaking and magnetic response of low-energy excitations in the ``dirty'' B phase of $^{3}\mathrm{He}$ in aerogel. A consistent interpretation of the data for the spin-diffusion coefficient, magnetization, and superfluid transition temperature is obtained by including correlation effects in the aerogel density.