Magnetic properties of Mn- and Eu-doped ZnS nanocrystals

The magnetic properties of Mn- and Eu-doped ZnS nanocrystals have been investigated. The results suggest that most of the Mn ions are coordinated on the surface of the nanocrystal, and the amount of Mn doped inside the nanocrystal does not exceed one per nanocrystal. Low-temperature magnetization shows the absence of antiferromagnetic interaction between Mn ions, in contrast to the bulk materials. For Eu-doped nanocrystal, the magnetic susceptibility data reveal the coexistence of Eu2+ and Eu3+ ions, though the starting material contains only Eu3+ ions. (C) 2003 American Institute of Physics.