Nuclear Magnetic Susceptibility Measurements ofHe3-He4Mixture Films

Nuclear magnetic susceptibility measurements of the ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ in dilute ${}_{}{}^3{}_{}{}^{}\mathrm{He}$-${}_{}{}^4{}_{}{}^{}\mathrm{He}$ mixture films are presented. At low ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ coverages ($d_3<0.1\mathrm{}$ layer), the ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ behaves approximately as a 2D ideal Fermi gas. For larger submonolayer ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ coverages, the low-temperature susceptibility is enhanced, increasing with increasing amounts of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$, contrary to the 2D ideal Fermi-gas model. No evidence for a phase transition in the ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ is seen.