Effect of Magnetic Scattering on the ${}^3\mathrm{He}$ Superfluid State in Aerogel

Pure ${}^3\mathrm{He}$ in highly porous aerogel forms an equal-spin pairing superfluid with transition temperatures suppressed from bulk values. We have measured the magnetic field dependence of the transition temperature from which it can be inferred that both magnetic and nonmagnetic quasiparticle scattering from solid ${}^3\mathrm{He}$ at the aerogel surface is important to the superfluid state. Replacement of the solid ${}^3\mathrm{He}$ on the surface of the aerogel with ${}^4\mathrm{He}$ gives rise to a unequal spin pairing superfluid phase.