Structure, optical, and dielectric properties of (Nd(NO ₃ ) ₃ ·6H ₂ O)-Epoxy composite materials for optoelectronic applications

This study demonstrates that incorporating Neodymium (III) nitrate hexahydrate (Nd(NO 3 ) 3 ·6H 2 O) into an epoxy resin matrix results in significant improvements in the composite’s structural, optical, and dielectric properties. Structural analysis revealed that increasing the Nd(NO 3 ) 3 ·6H 2 O filler concentration results in reduced crystallite size and tailored internal strain. At the same time, optical characterization showed a substantial narrowing of the indirect band gap from 3.628 eV in pure epoxy to 2.521 eV at 2.0 wt% filler, and a decrease of the direct band gap from 4.429 to 4.131 eV. Increases in dispersion energy accompanied these changes ( E d ) from 0.076 to 0.546 eV, and the static refractive index from 1.00462 to 1.070182. Dielectric measurements indicated an enhanced real part of the dielectric constant in the UV region (from ∼1.02 to >1.08) and low dielectric loss tangent (tan δ < 0.0014 over 300–2500 nm), with plasma and damping frequencies reaching 6.3 × 10 14 Hz and 5.7 × 10 30 Hz, respectively, for the highest filler loadings. Notably, 0.5 wt% Nd(NO 3 ) 3 ·6H 2 O exhibited the highest permittivity and minimum loss, making it the optimal composition for advanced energy-storage capacitors. These tunable properties confirm the utility of Nd(NO 3 ) 3 ·6H 2 O epoxy composites for energy storage and optoelectronic applications, especially within the 0.5–2.0 wt% loading range.