Influence of NiO on structural, optical, and magnetic properties of Al2O3-P2O5-Na2O magnetic porous nanocomposites nucleated by SiO2

Amorpho-structural and magnetic analysis of Al2O3-P2O5-Na2O/NiO magnetic porous nanocomposites in the influence of SiO2 as a nucleating agent is studied. Concurrently, the effect of the incorporated NiO nanoparticles on the structural, morphological, optical, and magnetic characteristics of the Al2O3-P2O5-Na2O porous nanocomposites is examined. XRD and FT-IR spectroscopy indicated the successful formation of Al2O3-P2O5-Na2O crystallizes, while the incorporation of NiO/SiO2 increased the total crystalline degree. TEM-results designate an increase in particle size of the phosphate-based crystallites as the NiO/SiO2 level increases, which corresponded to the higher crystallization in the sodium aluminophosphate (Al4Na7P9O32) nanocomposite. The FT-IR results showed that these modified sol-gel reactions are a result of acid hydrolysis of the Al-O-P and Na-O-P bonds and the influence of Si-O-OH, leading to network termination by POH groups and octahedrally solvated Al atoms (with strong quadrupole interaction) with the SiOH groups. With the introduction of NiO/SiO2, the fundamental band gaps are found to be 3.89, 3.93, 3.98, and 4.05 eV for direct allowed transitions. In the case of the indirect transition, the energy of the bandgap were 3.42, 3.57, 3.63, and 4.75 with the introducing of NiO/SiO2. The saturation magnetization increased from 0.11 to 0.38 with increasing NiO content from 0.15 to 0.25%. Also, the switching field distribution (SFD) was investigated. The obtained optical and magnetic properties for Al2O3-P2O5-Na2O/NiO magnetic porous nanocomposites supported with silica which make them an excellent candidate for high-performance optics, biocompatible systems, solid-state electrolytes, fast ion-conducting materials, and opto-magnetic devices.