Structural and Optical Properties of Liquid Crystalline Binary Mixtures with Dy3+ Phosphor Nanoparticles

Abstract

In the current study, the structural and optical characteristics of a binary mixture composed of p-(npropyloxy) benzoic acid (3OBA) and p-(n-butoxy) benzoic acid (4OBA), integrated with varying concentrations (1, 1.5, and 2 wt.%) of Dy³⁺:Li₄Zn(PO₄)₂ phosphor nanoparticles (NPs), are systematically examined. The synthesized liquid crystalline (LC) nanoparticle mixture was characterized using a range of analytical techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, UV-visible spectroscopy, and polarizing optical microscopy (POM). XRD analysis revealed that the size of the Dy³⁺-doped phosphor NPs in the LC mixture was approximately 85.23 nm. SEM images confirmed the uniform dispersion of Dy³⁺-doped phosphor NPs within the LC mixture. FTIR spectroscopy further corroborated the presence of functional groups associated with Dy³⁺-doped phosphor NPs in the synthesized compound. The optical bandgap determined from Tauc’s plot was increased by 0.62 eV due to doping of nanoparticles. Additionally, POM imaging revealed the phases of both pure and nanoparticledispersed LC mixtures, showing minimal changes in the nematic transition temperatures. Studies confirm that the synthesized liquid crystal nanoparticle mixture is an excellent material useful for microwave applications.