Surface-Induced Ferromagnetism inHe3

Abstract

Pulsed NMR measurements of the susceptibility and the transverse and longitudinal relaxation times of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ intermixed with 9 nm of carbon particles have been performed down to 0.4 mK. The results indicate that the first atomic layer has an antiferromagnetic exchange interaction. The intermediate solid-liquid region, ∼5 atomic layers thick, favors ferromagnetism and approaches a ferromagnetic transition at the lowest temperatures.