Cd_1−xMn_xTe ultrasmall quantum dots growth in a silicate glass matrix by the fusion method

In this study, we synthesized Cd_1−xMn_xTe ultrasmall quantum dots (USQDs) in SiO₂-Na₂CO₃-Al₂O₃-B₂O₃ glass system using the fusion method. Growth of these Cd_1−xMn_xTe USQDs was confirmed by optical absorption, atomic force microscopy (AFM), magnetic force microscopy (MFM), scanning transmission electron microscopy (TEM), and electron paramagnetic resonance (EPR) measurements. The blueshift of absorption transition with increasing manganese concentration gives evidence of incorporation of manganese ions (Mn²⁺) in CdTe USQDs. AFM, TEM, and MFM confirmed, respectively, the formation of high quality Cd_1−xMn_xTe USQDs with uniformly distributed size and magnetic phases. Furthermore, EPR spectra showed six lines associated to the S = 5/2 spin half-filled d-state, characteristic of Mn²⁺, and confirmed that Mn²⁺ are located in the sites core and surface of the CdTe USQD. Therefore, synthesis of high quality Cd_1−xMn_xTe USQDs may allow the control of optical and magnetic properties.