Fe-Ni Co-Doped Al2O3 Nanoparticles: Synthesis, Structural, Optical and Magnetic Properties
Year: 2026
Type: article
Abstract: Fe-Ni co-doped Al 2 O 3 nanoparticles were produced using high-energy ball milling and annealing at 1100 °C for 12 h. The samples were pure γ-Al 2 O 3 , pure annealed Al 2 O 3 (1100 °C), S-1: Al 1 . 94 Fe 0 . 03 Ni 0 . 03 O 3 , and S-2: Al 1 . 91 Fe 0 . 03 Ni 0 . 06 O 3 . X-ray diffraction revealed the transformation of the cubic γ-Al 2 O 3 phase into an α-Al 2 O 3 rhombohedral phase. The lack of secondary crystalline phases and the consistently lower-angle shift of the α-Al 2 O 3 (113) peak from 43.44° for pure annealed Al 2 O 3 to 42.37° for S-1 and 41.99° for S-2 indicate Fe-Ni-induced lattice expansion and structural deformation. Crystallite size increased from 4.694 nm for pure γ-Al 2 O 3 to 36.056 nm for annealed Al 2 O 3 , 38.758 nm for S-1, and 32.215 nm for S-2, indicating higher Ni content and increased lattice strain. TEM analysis showed agglomerated nanoparticles with average particle sizes of 7.96, 78.28, 85.96, and 30.72 nm for pure γ-Al 2 O 3 , annealed Al 2 O 3 (1100 °C), S-1, and S-2, respectively. EDS revealed the presence of Al, O, Fe, and Ni without foreign impurities, whereas FTIR spectra indicated the persistence of the Al-O framework and dopant-induced modifications of the local coordination environment. UV-Vis diffuse reflectance analysis showed that the estimated optical band gap increased from 3.03 eV for pure γ-Al 2 O 3 to 4.301 eV after annealing, then decreased to 3.957 and 3.449 eV for S-1 and S-2, respectively, demonstrating band-gap narrowing with increasing Ni content at a fixed Fe content. Under 240 nm excitation, Fe-Ni co-doped Al 2 O 3 exhibited violet-blue emission across 390-468 nm, with a dominant peak at 406 nm. Increasing the Ni content from S-1 to S-2 reduced the PL intensity without appreciably shifting the emission peaks, consistent with concentration quenching. Room-temperature magnetic measurements revealed a nonlinear response approaching saturation for pure γ-Al 2 O 3 , whereas pure annealed Al 2 O 3 (1100 °C), S-1, and S-2 exhibited predominantly linear, unsaturated responses within ±3 T. S-2 showed higher magnetization than S-1 at the same applied field. These nanoparticles are promising for defect-engineered optical materials, UV-blue emission, catalytic supports, and dilute magnetic oxide applications.
Source: Ceramics International
Language: English
Topic: ZnO doping and properties
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,830
OpenAlex ID: W7224968671