Magnetic nanoribbons!

Owing to their nanoscale spintronic applications, doping of semiconductor nanocrystals by transition-metal ions has attracted tremendous attention . However, such doping is difficult to achieve in low-dimensional strongly quantum confined nanostructures by conventional growth procedures. In a recent report in Nature materials, researchers from korea in collaboration with american researchers have demonstrate that the incorporation of manganese ions up to 10% into CdSe quantum nanoribbons can be readily achieved by a nucleation-controlled doping process.

The cation-exchange reaction of (CdSe)13 clusters with Mn2+ ions governs the Mn2+ incorporation during the nucleation stage. This highly efficient Mn2+ doping of the CdSe quantum nanoribbons results in giant exciton Zeeman splitting with an effective g-factor of ~600, the largest value seen so far in diluted magnetic semiconductor nanocrystals. The sign of the s–d exchange is inverted to negative owing to the exceptionally strong quantum confinement in our nanoribbons. figure on the right show the theoretical investigation of Mn2+ doping of CdSe clusters.

This novel nucleation-controlled doping strategy opens the possibility of doping various strongly quantum confined nanocrystals for diverse applications.

Ref: Nature Materials 9, 47 - 53 (2009)