Unexpected Property: Increase in the Magnetic Interactions of Cd1-yMnyS Nano-Sized Particles with Decreasing Particle Size

The relationship between particle size and bandgap energyin magnesium-containing quantum dots is reported here for the first time. A reverse micellar process was used in the synthesis of the Cd1–yMnyS quantum dots, a procedure whereby the size and composition of the quantum dots can be independently controlled. This allowed detailed investigation of the magnetic interactions between Mn2+ ions and the electron bands of CdS, and between Mn2+ ions themselves, and of how these interactions vary with the size and composition of the Cd1–yMnyS quantum dots.