Influence of Mo doping on the structural, Raman scattering, and magnetic properties of NiO nanostructures

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2024-10, Vol.130 (10), Article 691
• Main Authors: Khalaf, A., Saghir, Rayane, Abdallah, A. M., Noun, M., Awad, R.
• Format: Article
• Language: English
• Subjects: Antiferromagnetism; Biomedical data; Characterization and Evaluation of Materials; Coercivity; Condensed Matter Physics; Crystal defects; Crystallites; Data storage; Dopants; Doping; Face centered cubic lattice; Hysteresis; Lattice vacancies; Lattice vibration; Machines; Magnetic properties; Magnetic saturation; Manufacturing; Molybdenum; Nanoparticles; Nanotechnology; Nickel oxides; Optical and Electronic Materials; Oxygen; Photoluminescence; Physics; Physics and Astronomy; Processes; Raman spectra; Raman spectroscopy; Room temperature; Surfaces and Interfaces; Thin Films; Valence; Vibration mode; X ray photoelectron spectroscopy
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-024-07816-w

In this work, the Ni 1-x Mo x O, (x = 0.000, 0.025, 0.050, 0.075, 0.100, and 0.150) nanoparticles were prepared employing the coprecipitation method. The X-ray diffraction (XRD) confirmed that all the samples have a face-centered cubic (FCC) structure with no secondary phases by the effect of the Mo-doping. The Mo-dopants yielded smaller crystallites, reaching a size of 9 nm with x = 0.150. The transmission electron microscope (TEM) images revealed agglomerated NiO nanoparticles with nearly spherical shapes varied to elliptical-like shapes upon increasing Mo concentration. The energy dispersive X-ray (EDX) confirmed the purity of the synthesized samples. The XPS analysis confirmed the valence states of the presented elements in the samples as Ni 2+ , Ni 3+ , Mo 6+ , and O 2− ions. The XPS detected the reduction of the nickel and oxygen vacancies, by studying the ratio of Ni 2+ /Ni 3+ and lattice oxygen (O L ) to vacant oxygen (O V ) peaks. The Raman analysis demonstrated the active vibrational modes of NiO, for all the samples, along with stretching Mo = O bonds for the doped samples. The Photoluminescence (PL) spectroscopy was employed to study the near band edge and deep level emissions, giving insight to the defect levels within the band gap. The PL affirmed the decrease of the oxygen vacancies upon Mo-doping. Besides, the magnetic hysteresis measurements at room temperature revealed the superparamagnetic contribution embedded in the antiferromagnetic matrix of NiO. The magnetization was tuned by Mo doping concentration, where it affected the saturation magnetization, coercivity, and remnant magnetization. Mo dopant can modify the magnetic property of NiO nanoparticles and can be a potential candidate in biomedical field and data storage applications. Graphical Abstract