Magnetic response of magnetic ion-doped nanocrystals: Effects of single Mn2+ impurity

We theoretically study the effects of single spin- 5/2 magnetic impurity (Mn2+) on the magnetic response of nanocrystals containing interacting electrons. The energy spectrum and magnetic susceptibility of II-VI spherical nanocrystals as a function of the electron number (Ne =1-8) and the location of Mn2+ ion are calculated by using the configuration interaction method. It is found that the sp-d coupling between the carriers and Mn2+ ion significantly affects the low-field paramagnetism, depending on electron number and the location of the ion. The competition between electron-electron interaction and the sp-d coupling leads to the pronounced anisotropy of magnetic properties, ground state transitions in magnetic field, and the violation of Hund's second rule.