Novel magnetism in He-3 nanoclusters

The magnetic susceptibility of He-3 nanoclusters embedded in a He-4 matrix has been measured from 0.5 to 10 mK at pressures from 2.88 to 3.54 MPa. Eve n the lowest pressure clusters have a solid fraction in the region of the p hase diagram where bulk solid is unstable. At 3.54 MPa, theta = -250 muK, e qual to that of bull; 3He for v = 21.3 cm(3)/mole. For 2.88 MPa, theta = 14 0 muK, indicating a ferromagnetic tendency, similar to 2D films at some cov erages. At intermediate pressures, chi has a peak near 1.05 mK, but with no discontinuity. Magnetic ordering in nanoclusters appears to be different t han the U2D2 phase of bull He-3.