Room-Temperature Ferromagnetism in Mn-Doped ZnO Nanoparticles Synthesized by the Sol-Gel Method

Sidra Kanwal; Muhammad Tahir Khan; Vineet Tirth; Ali Algahtani; Tawfiq Al-Mughanam; Abid Zaman

doi:10.1021/acsomega.3c03418

Room-Temperature Ferromagnetism in Mn-Doped ZnO Nanoparticles Synthesized by the Sol-Gel Method

ACS Omega. 2023 Jul 26;8(31):28749-28757. doi: 10.1021/acsomega.3c03418. eCollection 2023 Aug 8.

Authors

Sidra Kanwal¹, Muhammad Tahir Khan¹, Vineet Tirth^{2

3}, Ali Algahtani^{2

3}, Tawfiq Al-Mughanam⁴, Abid Zaman¹

Affiliations

¹ Department of Physics, Riphah International University, Islamabad 44000, Pakistan.
² Mechanical Engineering Department, College of Engineering, King Khalid University, Abha 61421, Asir, Kingdom of Saudi Arabia.
³ Research Center for Advanced Materials Science (RCAMS), King Khalid University, Guraiger, P.O. Box 9004, Abha 61413, Asir, Kingdom of Saudi Arabia.
⁴ Department of Mechanical Engineering, College of Engineering, King Faisal University, P. O. Box 380, Al-Ahsa 31982, Kingdom of Saudi Arabia.

Abstract

In the current work, pure ZnO and Mn-doped ZnO nanoparticles were synthesized by the sol-gel autocombustion method. Structural analysis and phase determination were done by X-ray diffraction, and a hexagonal wurtzite structure was exhibited with disparate microstructures for all samples. Mn²⁺ ions were well composed, as evidenced by the fluctuation of lattice parameters, dislocation density, and lattice strain. Crystallite size decreases from 38.42 to 27.54 nm by increasing the doping concentration. Field emission scanning electron microscopy results shows the combination of evenly distributed spherical-like and hexagon-like structures. Fourier transform infrared spectra revealed that when Mn content increased, the absorption bands red-shifted. The drop in the energy band gap from 3.25 eV for ZnO to 2.99 eV for Zn_0.96Mn_0.04O was predicted by ultraviolet-visible absorption spectra. This red shift in the energy band gap can be explained by the sp-d exchange interaction between the band electrons of ZnO and localized d electrons of Mn. A study of magnetic properties revealed the change of the diamagnetic attribute for pure ZnO to the room-temperature ferromagnetic attribute of doped samples. In the current study, room-temperature ferromagnetism was achieved for Mn-doped ZnO nanoparticles, which can serve as a desirable option for practical applications in the future.