Structural, magnetic, and luminescent properties of NaGdF₄:Nd³⁺@Fe₃O₄ nanocomposites

The diverse applications of nanomaterials, and their rapidly increasing demand, have spurred the development of novel multifunctional materials. As such, this study aimed to synthesize and characterize a magneto-luminescent nanocomposite, composed of magnetite and fluorescent quantum dots (NaGdF₄:Nd³⁺@Fe₃O₄). Nanomaterial synthesis was accomplished through solvothermal and co-precipitation methods. Stable nanoparticles (NPs) with a zeta potential of -19.57 ± 0.42 mV, and a size of 4.55 ± 1.44 nm were obtained. The crystalline structure of the NPs, verified via x-ray diffraction, affirmed the hexagonal pattern of the NaGdF₄:Nd³⁺NPs and the inverse spinel pattern of Fe₃O₄NPs. In the diffraction pattern of the NaGdF₄:Nd³⁺@Fe₃O₄NPs, only the phase pertaining to the Fe₃O₄NPs was identified, indicating their influence on the nanocomposite. Magnetic measurements revealed the superparamagnetic behavior of the material. Photoluminescence spectra of NaGdF₄:Nd³⁺and NaGdF₄:Nd³⁺@Fe₃O₄NPs verified the luminescent emission around 1060 nm; a feature of the radiative transitions of Nd³⁺ions. Based on the assessed characteristics, the nanocomposite's multifunctionality was confirmed, positioning the material for potential use in various fields, such as biomedicine.