Crystal structure and magnetic properties of the Y2.97Gd0.03Fe5−xLaxO12 compound: an experimental and theoretical investigation

• Published in: Journal of materials science 2024-09, Vol.59 (36), p.16884-16899
• Main Authors: Gonçalves, M., Matilla-Arias, J., Penha-Caland, J., Vilca-Huayhua, C., Coaquira, J. A. H., Guerrero, F., Guerra, Y., Viana, Bartolomeu C., Peña-Garcia, Ramón R.
• Format: Article
• Language: English
• Subjects: Anisotropy; Cations; Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Coercivity; Crystal structure; Crystallography and Scattering Methods; Diffraction patterns; Elongated structure; Ferrous ions; Gadolinium; Irregular particles; Magnetic properties; Magnetic saturation; Materials Science; Mossbauer spectroscopy; Parameters; Polymer Sciences; Sol-gel processes; Solid Mechanics; Stoichiometry
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-024-10209-2

In the present work, we have investigated the crystal structure and magnetic properties of the Y 2.97 Gd 0.03 Fe 5− x La x O 12 (Gd-La co-doped YIG) compound (0.00 ≤  x  ≤ 0.05) obtained by the citrate sol–gel method. Rietveld refinement of the X-ray diffraction patterns provided the lattice parameter ( a ) values, which increased from 12.387(2) to 12.468(2) Å as the La 3+ content increased. Raman measurements confirmed the single-phase formation, whereas transmission electron microscopy (TEM) revealed elongated and irregular particles. The Mössbauer spectroscopy confirmed the presence of Fe 3+ and Fe 2+ cations and the coexistence of Fe 2+ and La 3+ cations in the octahedral and tetrahedral sites. Nonetheless, using a phenomenological model, it was suggested that the Fe 2+ and La 3+ ions tend to occupy preferentially the octahedral sites in the YIG structure. Further, the correspondence between the experimental and theoretically predicted saturation magnetization values indicated that the compound stoichiometry can be described by the chemical formula Y 3 + 2.97 Gd 3+ 0.03 Fe 3+ 5− x − y La 3+ x Fe 2+ y O 2− 12− y /2 . Magnetic parameters such as saturation magnetization, anisotropy constant, remanent magnetization, and coercive field values were computed and discussed as a function of cations distribution in the YIG crystal structure.