Journal article

Er3N@C80 exhibits sharp optical emission lines in the near-infrared attributed to fluorescence from the Er3+ ion. Here we demonstrate that high magnetic fields cause this spectrum to split, corresponding to transitions from the lowest field-split Kramers doublet of the 4I13/2 manifold to the four lowest field-split levels of the 4I15/2 manifold. The internal structure of these fullerenes can be spatially aligned with a preferred orientation under high magnetic field; the effect of alignment i...