Structural, Optical, and Magnetic Properties of Gd Doped CdTe Quantum Dots for Magnetic Imaging Applications

Induced room-temperature ferromagnetic behavior (RT-MF) of Gd doped CdTe (GDC) quantum dots (QDs) is reported. Pure CdTe QDs were synthesized by colloidal route using thiol stabilizers in an aqueous medium. The magnetic moments were induced by the inclusion of Gd in CdTe QDs. The effect of Gd ion substitution in CdTe lattices was characterized by X-ray diffraction which confirmed the formation of cubic zinc blende structure. The optical response of the prepared QDs was studied via UV-vis absorption spectroscopy, which indicated that Gd ion substitution alters the optical response toward a longer wavelength; this is further confirmed by corresponding emission analysis through Fluorescence emission spectroscopy. Quantum yield measurements confirmed that the GDC QDs give better quantum yield than pure CdTe QDs through the substitution of Gd ions. The formation of CdTe QDs with Gd ion substitution was confirmed by binding energy analysis through X-ray photoelectron spectroscopy. RT-MF of GDC QDs was revealed by vibrating-sample magnetometer measurement. Hence, the prepared GDC QDs were determined to be a vital DMS material for room-temperature spintronics applications.