Synthesis and characterizations of europium chalcogenide and tellurium nanocrystals

Abstract

Facile one-step syntheses of colloidal EuS, EuTe and Te nanocrystals are presented in this thesis. The formation of single crystalline monodisperse nanocrystals, with sizes finely controlled by synthetic conditions, was confirmed by x-ray diffraction and high resolution transmission electron microscopy analysis. The exciton transition of EuS and EuTe nanocrystals blue-shifts to higher energies with decreasing particle sizes, as revealed by optical absorption and photoluminescence measurements. The feasibility of synthesizing monocrystalline EuS nanorods and EuTe nanospindles was also demonstrated, making them potentially viable materials for device applications. Low-temperature magnetic measurements show that as-synthesized EuTe nanoparticles show pronounced superantiferromagnetic transition between. Te nanocrystals were well separated into two size regimes and assembled into films by eletrophoretic deposition.