Fermi-Liquid Behavior ofHe3Adsorbed on Liquid Helium

Some properties of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ adsorbed on the surface of liquid helium are determined from measurements of the surface and interfacial tension of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$-${}_{}{}^4{}_{}{}^{}\mathrm{He}$ mixtures. As a mixture approaches phase separation, the ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ adsorbed on the surface grows continuously into the upper, ${}_{}{}^3{}_{}{}^{}\mathrm{He}$-rich phase. At all temperatures the limit of low surface density is well described by the Andreev model, although there is some evidence for a weak, attractive quasiparticle interaction.