Cu-doping-induced modulation of crystal structure and magnetic anisotropy in Dy3CuxFe5-xO12 garnet nanocrystals

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2023-07, Vol.129 (7), Article 481
• Main Authors: Bharathi, R. Niruban, Ramachandran, Tholkappiyan, Rekha, G.
• Format: Article
• Language: English
• Subjects: Applied physics; Characterization and Evaluation of Materials; Coercivity; Condensed Matter Physics; Copper; Crystal structure; Doping; Fourier transforms; Garnets; Grain size; Hydrothermal crystal growth; Infrared spectroscopy; Iron; Machines; Magnetic anisotropy; Magnetic properties; Magnetic saturation; Magnetometers; Manufacturing; Materials science; Nanocrystals; Nanotechnology; Optical and Electronic Materials; Photoelectrons; Physics; Physics and Astronomy; Processes; Spectrum analysis; Substitutes; Surfaces and Interfaces; Thin Films; Valence; Whiskers (metals)
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-023-06753-4

The research investigated how the replacement of iron (Fe) with copper (Cu) ions affects the formation of crystals and magnetic properties in Dy 3 Fe 5-x Cu x O 12 (with x values of 0.0, 0.2, 0.4, and 0.6) created using the hydrothermal method. X-ray diffraction analysis confirmed that all the samples consisted of garnet-type-cubic crystals and exhibited a nanocrystalline nature. The grain size (71.01–65.51 nm) and lattice parameter (12.38–12.31 Å) decreased as the level of copper doping increased up to 0.06, indicating a significant substitution of copper in the iron sites. Fourier-transform infrared spectroscopy revealed distinct vibrational bands characteristic of DyIG and confirmed the replacement in octahedral and tetrahedral sites. Scanning electron microscopy analysis showed the presence of nanometer-sized grains with a whisker-like shape. X-ray photoelectron spectroscopy confirmed the valence states of Dy, Cu, and Fe as Dy 3+ , Cu 3+ , Cu 2+ , Fe 3+ , and Fe 2+ . The vibrating sample magnetometer demonstrated that the substitution of Fe with Cu in the A and D-sites resulted in a reduction of the saturation magnetization (Ms) from 14.41 to 7.46 emu/g within the range of 0.000 ≤ x ≤ 0.060. Changes in coercive fields at different dopant concentrations were attributed to variations in the magnetocrystalline anisotropy constant.