Magnetic Ordering in 3He Nano-Clusters

Simultaneous measurements of magnetic susceptibility from 0.5 to 10 mK and pressure from 2.88 to 3.54 MPa have been made in 3 He nano-clusters embedded in a 4 He matrix, following phase separation. The susceptibility of the 3.54 MPa, all-solid sample behaves similarly to that of bulk 3 He for v=21.3 cm 3 /mole, with a Weiss constant (theta) =-250(mu) K. For the 2.88 MPa, liquid-droplet sample, (theta) =140(mu) K, indicating a ferromagnetic tendency, similar to 2-D films at some coverages. At intermediate pressures, X has a peak near 1.05 mK, but without a discontinuity. For all samples, X had a solid-like contribution to the lowest temperatures. Magnetic ordering in nano-clusters appears to be different than the U2D2 phase of bulk 3 He.