Investigation on structural, morphological, vibrational, magnetic, linear and nonlinear optical properties of Zn²⁺-substituted NiAl₂O₄ nanoparticles

Chemical co-precipitation was used to successfully synthesis of nanocrystalline Ni_1−xZn_xAl₂O₄ (where 0 ≤ x ≤ 0.5). The resultant nanoparticles have a crystalline cubic spinel structure, according to analysis using X-ray diffraction (XRD). The determined crystal sizes for NiAl₂O₄ and Zn-doped NiAl₂O₄ are 36 and 15 nm, respectively. The band gaps of the materials were calculated to be 3.51 and 5.47 eV, respectively. The synthesis of zinc-doped nickel aluminates was confirmed by infrared (IR) studies, which showed the bond formation of the synthesized nanoparticles. Notable IR bands at 495 cm⁻¹ corresponding to octahedral-metal (Ni–O) stretching and a band at 563 cm⁻¹ corresponding to tetrahedral metal stretching (Al–O) were identified. The synthesized nanoparticles had ferromagnetic behavior, and M–H loop analysis was used to assess the magnetic properties of the particles, such as saturation magnetization (Ms), coercivity (Hc), and remanent magnetization (Mr). Z-scan technology was used to determine nonlinear optical parameters such as χ⁽³⁾ (third order nonlinear susceptibility), n₂ (nonlinear refraction), and β (nonlinear absorption). Further evidence supporting these material´s potential as viable options for use in devices such as optical switches and optical power limiters comes from the results of optical limiting experiments. In essence, our findings underscore the promising potential of Zn-doped NiAl₂O₄ nanoparticles for a wide range of applications in optics, magnetics, and beyond. The comprehensive characterization presented in this study lays a solid foundation for further exploration and exploitation of these nanoparticles in various technological fields.